More capacity for the same cost is the case with double-decker commuter cars -- if they can fit into tunnels, that is. Bi-level train were once more common in the commuter trains serving NYC. However, these cars can have their own disadvantages.
The main disadvantage of multi-level cars for Metro-North is that they would not be self-propelled (also called electric-multiple-units, or EMUs), each receiving electricity from either a third rail or overhead catenary, as there are short gaps in the third rails in the maze of tracks under Grand Central Terminal, and potential solutions, such as diesel/electric locomotives, have their own disadvantages.
"Two-level trains cost the same as their single-story counterparts, and can carry a third more passengers." The trains could also fit in the tunnels.
"Double-decker trains, then called "up and downs," were commonplace on the Long Island Rail Road from the late 1930s to the late 1960s; a more modern version began operation in 1998. New Jersey Transit has run double-deckers since 2005.
Officials at both commuter railroads say the bilevel trains receive rave reviews from customers, particularly because their interior layouts eliminate the hated middle seat."
Note: Article also reports on the bar cars that Connecticut is consider adding to its fleet, noting that plans have changed from purchasing new cars to retrofitting existing cars.
Thanks to NYT-commuting-transit alerts
Read the full story: Metro-North Considers Buying Double-Decker Trains
Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.
California plans to bury El Niño’s downpour
If the state plays its cards right, it may be able to store a billion acre-feet of El Niño’s water in aquifers.
Desperate measures: Advocates weigh draining Lake Powell to fill Colorado River
Draining the reservoir could reduce evaporation losses by a couple hundred thousand acre-feet.
Mamdani’s pied-à-terre tax survives legal challenge
A panel of judges found that the plaintiffs failed to demonstrate injury as a result of New York City's implementation of the tax.
Eastern Nebraska is running out of electricity
Data centers and electrification are straining eastern Nebraska’s grid, throttling economic development.
Seattle passes record-breaking transit services expansion
Proposition 1 will double the city’s transit tax to add 95,000 more bus trips and preserve 180,000 bus trips annually.
FREE Course: Walkable City 1: Why Walkability?
After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.
Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold
The course focuses on the opportunities and imperatives that shape reinvention of mall sites.
City of Rosemead
Rutgers University, Edward J. Bloustein School of Planning and Public Policy
One Hundred Miles
University of Michigan School for Environment and Sustainability (SEAS)
Hunter College, City University of New York (CUNY)
The Architects Foundation
City of Cambridge
Montrose County
The Pocatello Development Authority