Plans for Montgomery County’s proposed rapid bus system hit a bump Thursday as planners spent hours debating whether the system as envisioned is necessary or even feasible. Aimed at alleviating gridlock, the network would rely on buses that run in dedicated lanes on many major roads, like Connecticut Avenue, Georgia Avenue and Route 355. The latest plans include 23 routes on 150 miles of road.

But planners at Thursday’s Planning Board meeting could not decide whether to build the system to fit the county’s current needs or to fit a vision of the county 40 years from now. Some pushed for more lanes and more routes, while others argued that making a bigger system would be unnecessarily costly and lengthen the process.