A decade or so ago, after reading some of Jane Jacobs' work, I became aware of the distinction between mixed-use and single-use neighborhoods. In those days, I imagined that in a well-functioning urban neighborhood, every non-polluting use would be mixed together, and the lion of housing would lay down with the lamb of commerce.
But for the past few months, I have lived just six blocks from Jacobs' Toronto house, in the Annex neighborhood. And in the Annex, I have learned that the distinction between sprawl and walkable urbanism is a little more subtle than the bumper-sticker phrase "mixed-use" suggests.In the Annex, as in conventional sprawl development (CSD), most businesses are on a few major streets, especially Bloor Street West between Spadina and Bathurst. Although Bloor has a few residences above shops, Bloor is primarily a commercial street.
So how is Bloor different from San Jose Boulevard (the sprawling commercial street of my former neighborhood in Jacksonville)? Bloor's distinction rests less on diversity of uses than on street design.
San Jose has a wide variety of commercial activities near some residential blocks, but is as wide as eight lanes in some spots- too wide to be comfortable for pedestrians. Bloor is only four lanes wide, and is thus relatively easy for pedestrians to cross. And on Bloor, nearly every commercial building immediately adjoins the sidewalk, rather than being set back from the sidewalk by yards of parking.
As a result, pedestrians can easily access shops, rather than dodging cars on the way to their destination. And because the nearby residential blocks are part of a grid system, neighborhood residents don't have to hop from cul-de-sac to cul-de-sac to reach Bloor's businesses. In sum, Bloor is pedestrian-friendly less because of mixed use than because of pedestrian-friendly street design and compact development.
The Annex's residential streets, like those in my old neighborhood in Jacksonville, are at least somewhat single-use: streets with large apartment complexes (St. George and Spadina near Bloor) have very few single-family structures, and other residential streets are dominated by houses and duplexes. So in a sense, the Annex's streets are as single-use as a typical suburban subdivision- both types of streets are dominated by one type of structure.
But there are two significant differences between an Annex street and a CSD street. First, some of the Annex houses have been cut up into small apartments; thus, on an Annex street, single-family houses and duplexes often coexist with very small apartment houses (though not with high-rises). More importantly, the Annex's residential streets are more compact than their equivalents in sprawl subdivisions: houses are closer together, and are often duplexes. Thus, more people live on an Annex street than live on a typical residential street in Jacksonville, which means that the Annex has the density to support good public transit.
In sum, what makes the Annex walkable is not so much that every street mixes uses; rather, it is that the commercial streets are easily accessible from the residential ones, thus creating a mixed-use neighborhood.
NOTE: To see some examples of what I am talking about, go to Google Street View at maps.google.com. To see Bloor, go to anyplace between 350 and 600 Bloor Street West in Toronto. To see a typical residential street, go to Albany Avenue, just north of Bloor (Jane Jacobs lived on this stretch of Albany). To see an apartment-oriented street, go to St. George St. or Spadina Road just north of Bloor. To see my old sprawl street in Jacksonville, go to 10000 San Jose Boulevard in Jacksonville.
Comments
A few other differences
Don't know how things are in the Annex, but here in Montreal one commonly finds small-scale commercial activities combined with mixed use development at the corners of such residential streets: the ubiquitous 'depanneurs' which are the equivalent of a convenience stores (http://www.urbanphoto.net/blog/tag/depanneurs/), small cafes and restaurants, laundromats, etc. Street corners are where the life of the community is at!
Also, there is very limited off-street parking, and certainly no 'parking lots' in front of a building, so cars cannot form a barrier between the 'pedestrian space' and the 'commercial space'.
I should have been clearer
I thought I was hinting at the parking issue by mentioning that the shops are in front of the sidewalk- but perhaps I should have been clearer in noting that there isn't much off-street parking in the Annex.
As far as street corners on residential streets go, most residential streets don't have commercial stuff even at street corners. However, I can think at least one exception to that generalization: Dupont Street a few blocks north of Bloor, which goes back and forth from residential to commercial, and is most intensely commercial at the corner of Dupont and Spadina (which may have something to do with the subway stop at that corner!)
History detour
A perceptive and incisive article, Michael.
A supplementaty view from history could widen our understanding of the Annex. One reads in Wiki:
"It [the Annex] is mainly residential, with quiet, tree lined one-way streets lined with Victorian and Edwardian homes and mansions, most of them built between 1880 and the early 1900s"
http://en.wikipedia.org/wiki/The_Annex
Note the "one-way" remark that would have been unheard of and unthinkable in 1880 but necessary and inconvenient today. Parking was neither an issue or a requirement, hence the fronting of properties. Now parking started to emerge behind the buildings (the only available space), and in overground or underground structures.
Note also the word "quiet" and imagine what this would have meant in 1880; not a wisper, an environment suitable for "mansions".
A short detour into the past sheds more light on what makes the Annex what it is.
wrong about one-way
Thank you for the kind remarks.
By the way, Wikipedia is wrong about the one-way streets: the major streets (Dupont, Spadina, Bloor) are all two-way.
But it is true that lots of buildings (though by no means all) have parking in back. My apartment building has parking in back, but many of the smaller buildings don't.
Why is one-way "inconvenient"?
Fanis, perhaps you could explain why you believe one-way streets are "inconvenient"? It doesn't seem so obvious, so maybe you can provide the specific examples you have in mind.
I could see that it may require a little extra thought and time for some drivers (although the time aspect may not even be true, depending on how the signal timing works on the one-way streets...).
From a pedestrian perspective, it should seem like a vast improvement. Traffic only comes from one way, so the pedestrians don't have the challenge of trying to time the window where they can dodge cars coming from both directions. And because the moving lanes are effectively reduced by the parking lanes, as you note, the crossing distance itself would be shorter.
Additionally, the surplus space from reducing the number of moving lanes often provides the opportunity to provide adequate bicycle facilities.
Perhaps someone might argue that the one-way streets result in extra circulation. Except, as you seem to suggest, the one-way streets have allowed more on-street parking. Since one of the most significant causes of additional circulation is drivers circling the block looking for an open parking space, I'm not sure you could argue that one-way conversions result in any additional circulation.
I'm not quite sure what would make one-way streets "inconvenient," so a little clarification might be informative. Thanks.
Still more on one-way
I was walking through the neighborhood today (for purposes completely unrelated to this post) and realized that one-way streets do exist in the Annex, but they serve a completely different function than in a sprawl-oriented city.
In a sprawl-oriented city like Jacksonville or Atlanta, one-way streets tend to be major streets near downtown. Since the streets are often four or more lanes to begin with, conversion to one-way turns these streets into speedways, which is what makes them inconvenient for pedestrians (See, e.g., the 1400 block of West Peachtree Street in Atlanta, where I used to work).
On the other hand, the major, four-lane streets on the Annex are all two-way. It is only some of the residential streets that are one-way; those streets are basically one lane streets (since on-street parking usually takes up the second lane). On these narrow residential streets, one-way conversion reduces the risk of head-on collisions without dramatically increasing traffic speeds.
Thus, it seems to me that one-way streets are one of these tools that are good for pedestrians in some situations and not in others: harmless or even beneficial on narrow, residential streets, but bad in wider, busier streets without on-street parking.
Conversion of Two-Way to One-Way
Conversion of existing two-way streets to one-way is generally considered inconvenient and anti-pedestrian because:
- It speeds up traffic, as Michael says.
- In cities with good bus service, it means longer walks to bus stops and less legibility of the bus stop system, since stops in different directions are on different streets.
- For bicyclists, it either increases the length of many trips or provides a temptation to ride unsafely against traffic.
- Likewise, for motorists, it can increase the length of local trips significantly. It is meant to speed up through traffic at the expense of local traffic.
The traffic engineer Walter Kulash has converted some one-way streets back to two-way, undoing the damage that traffic engineers did in the 1950s and 1960s when they made them one-way, in order to revitalize those streets economically by making them more pedestrian-friendly.
However, as Michael says, one-way does make sense on streets that are so narrow that they are just one lane, where the narrowness of the street keeps the traffic slow.
New York converted its avenues to one-way some time around 1960, making people walk longer distances to bus stops. As I remember, Jane Jacobs criticized this change in Death And Life (1961). For a video that shows Fifth Ave. when it was two-way, search on YouTube for Butterfield 8, which I believe was released in 1960. I know you are watching that movie just to look at Fifth Ave, not to look at Elizabeth Taylor.
Charles Siegel
Still not clear that one-way streets are not pedestrian friendly
You make several important and thoughtful points. It is not at all clear to me, though, that one-way conversions make traffic faster or more dangerous even on wider avenues, though. I have long suspected that the disdain many planners show toward one-way streets was more firmly rooted in a simplistic assumption that anything good for cars has to be bad for cities, rather than careful observations of how streets are actually performing.
Let's ponder this a little more:
Speed
It is inaccurate to say that one-way streets cause drivers to speed up. One-way streets are designed to reduce travel time, which they do by establishing signal progression. The reduction in time, however, comes from less time waiting at red lights, not increased speeds.
Note that when signal progression is established, drivers are given a better motivation to stay at the posted speed limit. Going faster only makes them wait longer at the next red light; there's nothing to gain. Since two-way streets cannot have signal progression, there is the constant temptation to "beat the light," motivating drivers to speed up. It's like the difference between a metronome and a countdown clock!
Bus stops
The legibility of the bus stops is a sound argument. Having to get the same bus in different locations is clearly less simple. If this is the worst thing that ever happened to transit passengers, though, we'd be in great shape. I would put this in the category of "minor nuisances."
I don't see how it it's possible that one-way conversions would have increased overall walking distances to bus stops. I suppose that if both your origin and your destination were on the precise street where the bus stopped, it would have increased your walk. Of course, if you were on the next street over where the bus didn't stop, it would have decreased your walk. If your office was midblock, you would have split the difference coming and going. The average walk should have been about the same (admittedly there would have been winners and losers...).
Perhaps more importantly, it decreased the trip time for bus passengers. It also allowed the bus companies to make more runs with the same number of buses, improving their cost effectiveness.
Bicyclists
Sure, it's a drag. I hate having to circle around the block, or dismount and walk my bike every time I come home. Again, though, this is a minor inconvenience. I'd rather take the extra roadway space for bike lanes that can be recaptured by converting two-way streets.
Trip length
The notion that the one-way street "significantly" increases the length of a trip is debatable. If the additional distance is "significant," it is a short trip we should be targeting it for a more sustainable mode, and the added inconvenience may help provide an incentive to consider another mode. This argument works better for wider avenues that already accommodated parking on both sides of the street, since the additional on-street parking gained from a conversion of narrower streets frequently reduces the extra circulation of drivers searching for open parking spaces.
Ease of crossing
I still contend that in many cases, if not most, the one-way street is easier for the pedestrian to actually get across. If moving lanes have been converted to parking, there is a shorter crossing distance. In all cases, there are fewer potential conflicting automobile movements. Moreover, the signal timing should generally work out in the pedestrian's favor with a one-way street network; more time should be available for pedestrian convenience precisely because the signal progression is more efficient at processing the vehicular traffic.
And, if you want to talk about New York City avenues, that's exactly what you'll see! Pedestrians have gained a lot of additional crossing time at most intersections as a result of the one-way conversions (even without the appropriate pedestrian signal timing). As a result of the signal progression, most intersections clear all the traffic well before the light changes, and New York's jaywalking culture takes advantage of this additional time with no conflicting traffic. That simply wasn't a possibility when Fifth Avenue was a two-way street.
It Is Clear To Me That One-Way Streets Are Less Ped Friendly
To respond briefly to your points:
Speed:
Increased speed is the biggest issue on two-lane streets with infrequent signals. When they were two-way, everyone had to drive at the speed of the safest drivers. When they became one-way, there was a fast-lane that impatient drivers could use to pass the safest drivers.
Bus Stops
"I don't see how it it's possible that one-way conversions would have increased overall walking distances to bus stops."
Imagine that you live on Fifth Ave. When it was two-way, You could catch the bus in front of your building when you left, and get off the bus in front of your building when you got back. When it became one way, the bus was in front of your building southbound, but you had to walk to Madison Ave. northbound - an extra block of walking that you never had to do before.
Bikes:
You admit that one-way streets are a drag for bikes. But I don't see that they add more space for bike lanes, as you claim. The street is the same width and has the same space for auto, parking, and bike lanes, whether it is one way or two way.
Trip Length
I said it significantly increases the length of short trips and is meant to accommodate long trips at the expense of short trips. You reply that it does not significantly increase the length of the average trip the short trips should shift to other modes. But one-way also makes bicycling and bus use less convenient, so people are less likely to shift other modes.
Conclusion
You conclude: "As a result of the signal progression, most intersections clear all the traffic well before the light changes, and New York's jaywalking culture takes advantage of this additional time with no conflicting traffic. That simply wasn't a possibility when Fifth Avenue was a two-way street."
This is the real key: you are saying that one-way streets accommodate more automobile traffic, and that is a benefit to pedestrians (since traffic clears the intersection) and to bus riders (since buses are less likely to be stalled in congestion).
But I would say that it is a mistake to accommodate more traffic in this way. Traffic increases to fill the street capacity allocated to it. Fifth Ave. is more congested now than it was when it was two-way.
We should deal with congestion through congestion pricing, parking policy, and similar measures to limit automobile use to the capacity of the streets. It does not work when we try to increase the capacity of the streets to accommodate the traffic: all that happens is that the traffic increases and the streets become less friendly to other modes.
You make the same argument that traffic engineers have been making since the days of Robert Moses, and it does not work.
Charles Siegel
pedestrian benefits don't count if they don't hurt drivers?
Let's try this again. I am a little hesitant to try, because the response you posted seems to repeat the same anti-car mantra without responding to the actual points already discussed. But these can be difficult concepts, and maybe I explained something poorly or missed your actual point, so let's have a careful review.
I think it should become clear that one-way streets are actually beneficial for pedestrians, bicyclists, and bus passengers.
Speed:
As discussed, drivers are encouraged by the design of two-way street signal timing to accelerate at signal lights. One-way street signal timing progression discourages this behavior. This is clearly in favor of safer intersections - where the majority of accidents occur. This is undoubtedly one of the reasons the empirical studies found that one-way streets are safer.
Bus Stops:
I thought this was clear the first time, but let's go over this again.
You give the example of the lucky person on Fifth Avenue who apparently is also destined to a location likewise sited on the street where the bus stops in the base case. This is a very selective example, and one I noted up front in the previous posting. Yes, in this selective case, that individual trip has the minor inconvenience of an extra one-block walk on one half of the round trip.
Your example fails to recognize the individual on Madison Avenue. That individual now benefits from a one-block improvement in the round trip. On average, there is no change - even though it will be an improvement for some passengers and slightly less convenient for others.
Getting across the street!
You seem to have neglected the discussion about the ability to shorten crossing distances, in many instances, and the simple fact that in every case the pedestrian is exposed to fewer conflicting turns. Turning vehicles are, after all, a leading cause of pedestrian accidents...
Bikes:
Converting two-way streets provides additional space a traffic engineer can use. Street design is often an inch hunt! Narrower, two-way streets in a residential context that are converted to one-way streets typically go from two lanes to a single travel lane. This provides ROW for the bike lane.
Likewise, on wider streets, busier streets, you can actually narrow the width of the travel lanes because you don't need to maintain the shy distance for head-on traffic. Narrowing travel lanes can also provide some of the traffic-calming needed to address concerns about increased speed. The space left over after narrowing the vehicular travel lanes - the bike lane.
If you ride a bike, you would probably also appreciate the reduced risk of dooring! On a one-way street, the bike lane is located on the left side wherever possible. This is the passenger side of the car (which is used far less given the number of SOVs). The risk of getting injured by a door - a leading cause of bicyclist accidents - is greatly lower.
Trip length/mode:
There is no credible reason to suggest that buses become less convenient with one-way streets. Quite the opposite. As we just reviewed, for an average bus trip (which does not generally stop AND end on the particular street where the bus stop is located) there is no change. However, because the signal progression speeds up the bus trip, and the pedestrian conditions are safer (as we already discussed...) buses should be more attractive.
Similarly, providing more safe bicycle lanes (additional ROW to create more lanes, lanes with less risk of dooring accidents) throughout the network could make bicycling more attractive, despite the need for some occasional detours or dismounting to walk the last block. Whatever minor inconvenience exists can be partially mitigated by properly siting the bicycle parking to allow the remaining distance to be comfortable traveled as a pedestrian, without having to walk the bike much at all.
Robert Moses?!!!
Let's take a breath here, shall we? I didn't suggest cutting an expressway through a neighborhood, for goodness sake. I'm saying that we should look at the facts and use the best evidence available to make good decisions. If there is credible evidence that shows the one-way streets are more dangerous, I would like to see it. I haven't seen it yet!
Traffic management:
In no way did I suggest that there was any goal to accommodate more vehicular traffic. That is a misunderstanding, and one that probably requires an anti-automobile perspective to misread in such a way. (I did suggest someone from the 19th century would be impressed that we are able to provide a greater sense of safety despite moving more traffic, but that's a long way from advocating more driving!)
I think my statements have been clear that by efficiently processing the traffic, more signal time can be provided to pedestrians. If we wanted to encourage more vehicles, we would keep the signal time to allow for traffic growth, rather than repurposing it for LPIs, Barnes Dances, and other benefits to pedestrians that are possible because of the available signal time. Additional signal timing can be used to benefit bus operations, by giving buses a queue jump.
Indicating that there are traffic management methods like congestion pricing and parking policies does not change the fact that pedestrians and bus passengers benefit when we make efficient, intelligent use of our street network. It also does not change the fact that one-way streets are simply safer. If this doesn't work for you, I invite you to provide substantive reasons why not.
Last Response On Two-Way Streets
I will just respond to a few points:
Buses used to go both ways on both Fifth and Madison. At the same time that Butterfield 8 showed 2-way Fifth, J.D. Salinger was writing about the Madison Ave. bus. Note that I initially said this point applied only to locations with good bus service.
If anyone proposed changing a two-lane two-way street into a one-lane one-way street with space for bike lanes, I would support that. I have never seen that happen, but I have seen many streets that were two-lane two ways and that were converted to two-lanes one way, and they have more aggressive traffic. Note that I said this issue applied when lights were widely spaced, which makes it difficult to control speed by timing lights.
You may not realize it, but you were talking about accommodating more traffic. You said one-way streets are better for pedestrians because traffic clears the intersection. We can expand this statement to the following:
1) when there was less traffic, two-way streets accommodated it.
2) now that there is more traffic, traffic doesn't clear the intersections with two-way streets
3) therefore, we should convert the streets to one-way to allow the increased traffic to clear the intersection (= to accommodate the increased traffic).
These conversions to one-way often accompanied freeway construction, to carry the traffic from the freeway-off ramp into the city. Hence, the Robert Moses connection. An example is the Fell and Oak couplet in San Francisco, made one-way to carry traffic exiting from the Central Freeway, still high-speed and unsafe because they are one-way even after the Central Freeway has been removed.
Charles Siegel
one-way streets don't have to increase vehicular volumes, either
I do not doubt you could identify particular locations or situations where a one-way treatment is inappropriate (perhaps there are gaps in the street network, intersections are widely spaced, etc.) I wouldn't disagree with that - you always have to assess the local conditions and make intelligent decisions.
However, given the existing evidence and all reasonable arguments, a firm opinion that one-way streets are not pedestrian friendly clearly would not lead to intelligent decisions.
I could care less about movie references; let's stick with the actual bus operations on Fifth and Madison. The fact both Madison and Fifth each had a bus route is meaningless from a passenger trip perspective. What share of passengers with a point of origin on Fifth Avenue got on the bus to get to a destination that was also on Fifth Avenue? How many instead got on the bus on Fifth Avenue to ultimately go to a store further downtown that was on Madison Avenue? Or maybe an office on Park Avenue? You're wasting a lot of time complaining about a meaningless level of impact. The improved trip times on the bus run are more real - yet you seem to dismiss them because they were also beneficial to cars.
Living in New York City, you should be well aware that the outer boroughs are filled with narrow, formerly two-way streets that were converted to one-way streets to allow parking on both sides. Many of these have subsequently had bicycle lanes added.
Also, here are NYC DOT drawings of a two-way to one-way conversion that creates a protected bike lane:
http://www.streetsblog.org/wp-content/pdf/Carmine_MD906_proposal.pdf These projects do exist.
Yet even if a pair of bi-directional lanes were converted to two lanes in the same direction of travel, there is greater possibility of creating a new bicycle lane, and any bicycle lanes existing or newly created will be safer because they're less vulnerable to dooring on the left side of the street. Note that, as previously discussed, the "inch hunt" makes it easier to create a bicycle lane where it wasn't possible before because you're only looking for space for one bike lane, not two, and as noted, you can also narrow the lanes. If there were two bike lanes, you can upgrade them for more protection. You may even be able to implement a fully-separated cycle track so the bicycle network can remain two-way safely, while gaining the benefits of the one-way vehicular operations. Note further, narrowing the vehicular moving lanes can have some of the traffic calming effect that seems to concern you, while further protecting cyclists.
Your concern about the aggressive drivers seems somewhat puzzling, though. You only seem to be concerned about them mid-block, where there are fewer accidents, rather than at the intersections where two-way streets create more points of conflict with pedestrians, including left-turning vehicles that try to dart through the oncoming traffic right across the crosswalk. Don't get me wrong - mid-block speeds are still important (kids have a tendency to rush out into the street), but let's at least be consistent. The trade-offs clearly point to safer conditions with one-way operations.
I realized exactly what I meant about signal timing, although you still seem to be misunderstanding or misrepresenting the point. Perhaps we can try one more time to clarify the point I am making by responding to your outline of the problem. Please set aside any dedication to penalizing cars for just a moment to recognize that this has nothing to do with increasing traffic volumes:
1) Two-way streets have staggered arrival times,
2) Because the arrival times are staggered, traffic continues to arrive through the end of the signal phase,
3) Therefore, if we were to convert the pair of streets to one-way operations, the progressive arrival times would allow us to maintain a superior level of service that cleared the same volume of traffic through the intersection in a shorter period of time, allowing us to dedicate more time to pedestrians. We may even be able to give buses more priority signal treatment!
As we continue to work through this problem, it becomes increasingly apparent that the only enduring argument against one-way streets is that they also benefit motorists.
Commissioner Barnes
I think you are unfairly critical of the work of people like Commissioner Barnes, too!
He was responsible for implementing efficient one-way streets, as well as being the biggest proponent of the all-pedestrian signal phase. To suggests dedicated professionals like him were unconcerned with pedestrians is outrageous and untrue.
another factor re one way vs. two way
"If moving lanes have been converted to parking, there is a shorter crossing distance."
An excellent point. A one-way street with on-street parking has the "traffic calming" benefit from the parking. But a wide one-way street without parking really does, I think, have faster traffic than a two-way without parking. Certainly that's my sense from having walked on (two-way) Peachtree and (one-way) West Peachtree a block away.
jury's out on speed... but one-way is safer
There may be a risk of higher vehicle speeds on one-way streets, although I still have to believe that depends largely on the signalization (and other local conditions).
The bottom line is that the empirical evidence suggests one-way streets are safer for pedestrians. Please refer to the FHWA's 2003 Review of Pedestrian Safety Research in the United States and Abroad (http://www.tfhrc.gov/safety/pedbike/pubs/03042/)
I'll be the first to admit I'm not very familiar with Atlanta, but my sense is there are many fewer pedestrians, buses, and taxis on West Peachtree. I would expect those activities to cause drivers to slow more on Peachtree. I would also be curious to know what speed limit was established and how West Peachtree is signalized.
weak empirical evidence?
I found a few paragraphs in the FHWA link talking about one-ways (which I think is the post referenced). It suggests that there are perhaps more crashes on two-ways. But this doesn't really put away the issue for me.
Given that one-ways (other things being equal) make a street effectively wider and thus make traffic faster, it would make sense that shops along that street would be less popular, because the faster a car goes the greater the difficulty it has slowing down to make a turn into a store. If this is true, there would be fewer interesting destinations such as shops on the street, which in turn means there would be fewer pedestrians going to those destinations. So the lower number of pedestrian/vehicle crashes might mean that the one way street attracts fewer pedestrians, rather than that a pedestrian's actual risk is lower.
Of course, this is all conjecture. But I thought I would throw out the possibility for discussion.
visibility issue
I seem to recall there was some debate back in the 60s or 70s about whether the storefronts on the less visible corners of one-way streets suffered from a lack of visibility. I don't remember much of the details offhand. I would expect it to become somewhat less important now; given the importance of the internet and growth of onboard GPS, I'm not sure businesses have to rely quite as much on being seen from a passing car.
In general, the concern seems rather overblown to me. If street corner visibility were really important for the viability of a business, we should expect to see failed midblock businesses anywhere.
The other part of your assumption about visibility seems to return to speed, although as already discussed it's not at all clear one-way streets increase speed. Most drivers get tired of speeding up and then waiting at lights, and will settle into the established speed limit under a signal progression.
That same speed assumption seems to be driving the question about pulling into a business. In some truly important ways, though, the ability to pull into a desired destination improves on one-way streets. It is easier to pull into every business on the left side of the street, because you no longer have to cross oncoming traffic.
The two studies cited by the FHWA may not be conclusive. At least there's something. I have yet to see any empirical evidence to support the bias against one-way streets that is so prevalent in planning circles.
The concern about differences in pedestrian volume is important, but it should also be basic for any transportation study. I find it unlikely the study would have been taken seriously had it failed to account for differences in pedestrian volumes. (Unfortunately, the original studies are old enough they're not available as a hyperlink.)
The logic on speed
I should probably have explained the basis for my assumption that one-way streets have faster traffic.
Assume a two-way, four-lane street. If you are driving along that street, you are basically part of two lanes of traffic going in the same direction. By contrast, if the street becomes one-way, there are now four lanes of cars going in that direction. So isn't it the norm that cars on a four-lane street would be going faster than on a two-way street?
(In fact, page 5 of this report cites higher speed as an advantage of one-way streets
http://www.wichita.gov/NR/rdonlyres/80D5F163-0D05-41A3-A731-0022BB27075B... )
And certainly it has been my experience that there aren't as many businesses on such streets- or if there are, they tend to be businesses that don't depend on impulse traffic. This might be because of increased speeds, or perhaps might be because one-ways are more cumbersome for motorists to navigate, and so they give up if they are not too dedicated to reach the destination.
speed - measured over what distance?
If there is a signal progression, I can't see any possible incentive to drive faster, just to wait longer at the next light, regardless of the number of lanes.
I can't say what exactly the Wichita report meant when it said "traffic speeds" (I think they meant to say there are shorter travel times), but let's consider terminology for a moment. You could use the phrase "traffic speeds" to refer either to the speed at a particular point, or the speed over a segment of roadway. For example, it could be accurate to say one-way streets had a higher "traffic speed" if they maintained a consistent 25 mph over the distance of 10 blocks, while over the same stretch the two-way streets had speeds of 35 mph between intersections combined time spent idling at signal lights. When we talk about safety, it is the speed of the vehicle when it hits something that matters, not its average over a distance.
In terms of speed, let's consider the intersections at two-way streets a little more. There is always an incentive to try "beating the light" where there is no signal progression, regardless of the number of lanes. This is especially true in situations where drivers can see all the lights on a stretch of two-way street all turn green at the same time; some drivers will "gun it" to get through as many lights as possible before the lights all turn red. That is, of course, not only dangerous when some of them fly through a red light a little late, but also very dangerous to drivers making left turns and consequently for the pedestrians in conflict with the left-turning vehicles focused on the threat of a high-speed collision with the oncoming traffic.
Even if we were to assume that vehicle speeds were faster overall (which is to say largely mid-block) on one-way streets, there is still every likelihood that the speeds at the intersections - where accidents with pedestrians and other vehicles mostly occur - would be faster on the non-progressive signal timed streets (i.e. two-way streets).
Note that the Wichita study's empirical evidence found observed vehicular speeds (in this case probably taken with a radar gun) were consistent with the posted speed limits along the one-way streets. Given that observation, if there is a concern about excessive speed, wouldn't it make sense to reduce the posted speed limit and make the necessary adjustments to the signal timing?
Of course, we should never forget the obvious caveat that it is never safe to try generalizing as an absolute rule. There could be instances where the one-way streets offer no progressive signal timing, where a lack of street connectivity would make the movements necessary to navigate around a one-way burdensome, or many other local circumstances that need to be considered. As a general rule, though, I still haven't come across credible evidence to support a movement toward two-way conversions.
I should admit there is an additional factor about visibility that comes to mind that I neglected before. Having to stop at a light practically forces drivers to look at the surrounding businesses. One-way signal progression takes that away. Chances probably are good that they lose some visibility. I'm just not sure I would put much consideration into trying to make businesses a little more visible at the risk of worsening safety and the level of service of the street network.
More from History
Thankfully, the conversation veered in the direction of one-way streets; we now have some well-informed views and facts about what they can and cannot do for pedestrians and for the city. It is clear that they could be inconvenient in certain circumstances which may be avoided or alleviated with good network planning. I referred to the one-way only from a historical perspective and to juxtapose the 1880 pedestrian environment, a complete ownership of the street, to today. (see images http://www.flickr.com/photos/22392855@N08/4139106263/ )
The restrictions on movement for pedestrians and drivers can be seen as necessary adaptations. The necessity to have one-way goes back to Pompeii (50 CE) when horse and cart ownership stood at 5%! http://www.pompeiana.org/ (Curiously the Annex is about the same size as Pompeii.)
Which returns us to history and the real subject of Michael’s article –mixed use. Reading from a quick historical sketch: “While today Bloor Street West is the commercial core of the area, it was once the residential core of the Annex. Some of the city’s wealthiest inhabitants once lived in the mansions of Bloor Street West, and ambled slowly beneath its fine canopy of trees. Today, Bloor overflows with hip shops, restaurants and clubs, but the keen eye can still spot a much-altered mansion behind a billboard”
And from Wiki under “Annex”:
“In 1886, Simeon Janes, a developer, created a subdivision which he called the Toronto Annex. First residents of the area included Timothy Eaton, patriarch of the Eatons Department Store, and George Gooderham, president of Gooderham & Worts Distillery. The Annex's Golden Era lasted until the 1920s, when the upper classes began to migrate northward to newer more fashionable suburbs in Forest Hill and Lawrence Park.”
One can ponder a few questions from these sketchy notes: What was the housing and social mix at that time? What was the commercial/residential mix? Where did its population work, worship, shop and play and how did they get there? And, finally, if the area was gradually becoming more walkable, income and ethnicity diverse and better served by transit, what prompted the upper classes to migrate further north?
The developer, for his part, optimized the use of land by creating some of the largest blocks in Toronto - up to 1100 feet long by 250 wide; five times the size of the “walkable” Portland blocks and similar to what is done in conventional suburbs today. The Annex was not the average affordable, compact, mixed-use, “urban” development that it has become 100 years later. Adaptation did more “design” than the original planners.
Can we add “Annexes” to the city perimeter today and anticipate that they will naturally be dense, diverse, mixed-use, affordable and walkable a hundred years from now?
Intersections are the key!
I am surprised that no one here has mentioned conflicts at intersections! The number of conflicting movements grows exponentially with the number of traffic directions. As a pedestrian, it is far easier to cross an intersection of one-way streets than an intersection of two-way streets. With one-way streets, there is always one crossing which is virtually conflict-free, whereas with two-way streets this is never the case. Accidents are far more likely to happen at intersections when there are 'surprises' - a car trying to turn left from a two-way street needs to navigate both the oncoming traffic as well as pedestrians who may be crossing their path from *either* direction on their left. Pedestrians crossing with the opposing traffic should be visible enough, but those crossing in the same direction as the car trying to turn left may be easily missed. Turning left from a one-way street onto a one-way street, and the driver only has to deal with the pedestrians - there are no vehicles crossing their path at all.
Add to this mix bi-directional bike-lanes, and the number of potential conflicts at each intersection just goes completely off the scale. No one knows where the next potential conflict is coming from!
Sure it might be necessary to walk an additional block to get to the bus stop, but in a dense urban environment that is nothing (I would not be saying that if the streets were spaced 500 meters apart).... And the last I heard it was easier to bike a block than to walk one. Although in my opinion the bicycle network should be more integrated with the pedestrian infrastructure so that 'counter-flow' bicycling would not be such a dangerous thing. Montreal is slowly starting to realize this and they have been adding 'reverse-direction' bike lanes on certain smaller one-way streets where there is a lot of bicycle traffic (http://www.urbanphoto.net/blog/2007/08/29/follow-the-sharrows/).
excellent point
The multiple potential conflicts were briefly mentioned, but you provide a very good explanation of the problem.
Thanks!
Thanks for an excellent discussion
Now that the discussion appears to have died down, I just want to thank everyone (urbanresidue and Charles Siegel especially) for an excellent discussion of an issue I had not given much thought to (one-way streets).
One-Way and Two-Way Streets
An article just appeared that is related to this old planetizen thread, so I am posting some quotes:
After the severe winters of 1978 and 1979, many of Chicago’s streets were converted from two-way to one-way to improve mobility during the winter and to allow plows to go through. However, two-way streets have many advantages over one-way streets. These ‘skinny streets’ reduce vehicle speeds and can also increase connectivity for all users by providing more ways to traverse the city’s grid. Skinny streets should be considered on all one-way streets that are wider than 30 feet.”
One resident's reaction:
Speed is the main concern. The width of the street and the low speed-humps make anything resembling “neighborhood” speed rare. Drivers build up speed coming from Western, headed to California, often disregarding stop signs as well. If there was a speed camera here we wouldn’t be surprised if drivers routinely hit 40+ mph. The road becomes an easy, fast westbound alternate to Division.
http://streetsblog.net/2012/09/13/making-neighborhood-streets-skinny-and...
Charles Siegel
New Study: Two-Way vs One-Way Streets
I just came across an article in Access magazine about this issue, which we discussed a couple of years ago.
Two-Way Street Networks: More Efficient than Previously Thought?
by Vikash V. Gayah
....
Our study uses an idealized traffic network model to directly compare the efficiency of one-way and two-way street networks. It finds that two-way streets may serve traffic more efficiently, especially when trips within the network are short.
http://www.uctc.net/access/41/access41_twoway.shtml