Peak hour tolls are $2 higher than non-peak, but much, if not most improvement in travel time may be attributed to the plunge in carpooling. Any charge for carpoolers creates a major disincentive to carpool, according to the report's focus groups.
"According to the study, ordered by the Metropolitan Transportation Commission after it restructured and raised tolls at the Bay Bridge beginning in July 2010, charging a discounted carpool toll of $2.50 caused 4,365 vehicles to abandon the carpool lanes daily - a 26 percent decline.
The other big change, the region's first congestion-based toll - a $6 charge during peak commute hours and $4 at other times - delivered time savings for drivers of as much as 16 minutes on some bridge approaches.
The biggest time savings was on the Interstate 880 approach from Union Street in Oakland to the toll plaza between 7 and 8 a.m. After the toll increase, the driving time dropped by 16 minutes for drivers paying cash. Before the changes, the drive took 32.7 minutes."
The findings may appear to conflict with an earlier UC study that showed that reduced usage of carpool lanes decreased travel speeds and increased congestion. That study dealt with the exclusion of solo-occupant hybrid vehicles from carpool lanes on July 1, 2011.