WASHINGTON, Dec 22 (Reuters) - U.S. passenger railroad Amtrak's next-generation high-speed Acela train cars ‌were delayed by ​more than four years ‍due to planning, ⁠design ⁠and track issues and a ‌desire ​for higher speeds that has not ⁠materialized, a ‍Senate ​report issued late on Monday said.

Amtrak's $2.3 billion program ‍to replace its high-speed trains along the northeast U.S. corridor lost $287 ​million ‍in revenue and unplanned maintenance costs because ​of extended use of the older Acela fleet, said Senate Commerce Committee chair Ted Cruz ​in a report.