Metro’s proposed new railcar model was met with skepticism from the agency’s board of directors Thursday because the new cars would be incompatible with the agency’s existing models, giving Metro less flexibility when moving trains through the system.

The proposed 7000 Series cars would be higher tech and lighter weight than Metro’s current railcars, but would be linked in groups of four instead of in pairs, forcing the agency to take four cars out of service when one malfunctions.