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
FULL STORY: Metro-North Considers Buying Double-Decker Trains

Trump Administration Could Effectively End Housing Voucher Program
Federal officials are eyeing major cuts to the Section 8 program that helps millions of low-income households pay rent.

Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

Ken Jennings Launches Transit Web Series
The Jeopardy champ wants you to ride public transit.

Washington Legislature Passes Rent Increase Cap
A bill that caps rent increases at 7 percent plus inflation is headed to the governor’s desk.

From Planning to Action: How LA County Is Rethinking Climate Resilience
Chief Sustainability Officer Rita Kampalath outlines the County’s shift from planning to implementation in its climate resilience efforts, emphasizing cross-departmental coordination, updated recovery strategies, and the need for flexible funding.

New Mexico Aging Department Commits to Helping Seniors Age ‘In Place’ and ‘Autonomously’ in New Draft Plan
As New Mexico’s population of seniors continues to grow, the state’s aging department is proposing expanded initiatives to help seniors maintain their autonomy while also supporting family caregivers.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
Heyer Gruel & Associates PA
Ada County Highway District
Institute for Housing and Urban Development Studies (IHS)
City of Grandview
Harvard GSD Executive Education
Toledo-Lucas County Plan Commissions
Salt Lake City
NYU Wagner Graduate School of Public Service