Metro officials broke ground Friday on a project that will significantly speed up service on the popular Orange Line rapid bus and ease the eventual conversion of the route to light rail.

One of the most successful bus routes in Metro’s transit network, the Orange Line runs between North Hollywood and Chatsworth, providing a key transit option along the San Fernando Valley’s major east-west corridors. The bus travels in its own lane and stops infrequently, but a ride from end-to-end currently takes about 50 minutes.

That could change once work wraps up on the new project, which will add crossing gates to 35 intersections along the route. A pair of aerial bridges will also be constructed for the bus at Van Nuys and Sepulveda boulevards, along with new stations above the street.

Expected to cost between $320 million and $393 million, these changes will ensure the bus is able to travel between stops more efficiently, without getting snarled in traffic. According to Metro, the aerial stations and gated crossings are expected to reduce the total length of a ride on the line by 20 percent.

The changes will also come in handy when, in coming decades, the bus is replaced by a train. Conversion of the line to light rail is one of the dozens of projects that Metro plans to finance with sales tax revenue gathered through Measure M.

That project is a ways off though; under the current project schedule, it’s expected to open in 2057. The agency may be able to accelerate that timeline, with the help of an outside company. Last year, Metro announced that it had received an unsolicited proposal from Texas-based company Fluor Enterprises for a public-private partnership to build and operate the line ahead of schedule.

Regardless of whether plans for a light rail line move forward faster than expected, the bus improvements will almost certainly wrap up first. Metro aims to have all the crossing gates and aerial bridges up-and-running by 2025. The project is one of 28 that the agency plans to complete in time for the 2028 Olympics.