Opponents of Honolulu’s elevated rail project are now raising the prospect of a Bus Rapid Transit (BRT) line as a substitute, citing Los Angeles’s Orange Line busway as an example.

This is surprising to me, because in Los Angeles, we are now committed to rail over BRT in our future transportation plans.

As a member of the Los Angeles County Board of Supervisors and a director of the Los Angeles Metropolitan Transportation Authority, I led the effort to build a rail line through my South Los Angeles district to Los Angeles International Airport. As we pushed hard for a rail system, we were sure of one thing: Our goal was a train, not a BRT.

Just as in Honolulu, some in Los Angeles had argued a BRT would cost less and provide many of the benefits of a rail line. My community rejected that premise. I and other Los Angeles Metro board members concluded a BRT simply would not give neighborhoods the same boost as a rail line.

We in Los Angeles are well aware that the investment in rail will not only provide faster and more reliable transportation, it will also do far more to elevate the quality of life for the communities it will serve. Rail is the hands-down winner in mobility — both transportation mobility and upward social mobility.

That is why the Crenshaw/LAX light rail line is being built in my district, not a BRT.

In Los Angeles, the Orange Line BRT was a good option in the San Fernando Valley because there was an abandoned rail right-of-way there. The busway did not have to take lanes away from a busy street because it could simply use that former railway path.

In other parts of Los Angeles, as in Honolulu, building BRTs would require disrupting existing streets, which makes a BRT far less attractive. So now that the Orange Line is completed, our top transit priority is expanding our rail network.

Since its opening in 2005, the Orange Line BRT has been studied by Los Angeles Metro, the Federal Transit Administration and other experts. The Orange Line has taught us some important lessons about the limits of a BRT. Among them:

» The BRT is slower than promised. Much slower.

The Los Angeles busway was supposed to cut travel time on its 14.5 mile route from 50 minutes to less than 30 minutes. In fact, the travel time for the entire route is now 43 minutes.

» Because BRTs run at street level and through intersections, they collide with cars, bicyclists and pedestrians.

Between October 2005 and April 2010, the line experienced 58 accidents at intersections. In its first month of operation, the busway experienced 709 near misses. The number did fall to 72 near misses by October 2006. But an elevated train would never be in the path of cars or people. There would be far less risk to human life, not to mention the large payouts that come with personal injury claims.

» Los Angeles spent less on the BRT than rail, but got less.

Los Angeles Metro has spent $26 million per mile on the Orange Line BRT — to cut travel time by 29 seconds per mile.

For these reasons, a BRT does not provide the same boost to economic development that a rail system brings. By taking up traffic lanes, obstructing car traffic at intersections and, in some cases, marring streetscapes by taking away pedestrian zones and street parking, a BRT can have a negative impact on a commercial or residential district.

Rail versus BRT is a question of cost versus value. That is why in Los Angeles, we are pleased to have used the BRT option where it made sense, but our focus now is rail.

If Honolulu abandons its rail project and with it the $1.55 billion in federal money designated for the rail line, Los Angeles will be among several metro areas eagerly seeking those funds. And if we are able to get any of that money, we will spend it on rail, not BRT.

Mark Ridley-Thomas represents 2 million constituents on the Los Angeles County Board of Supervisors. He is a director of Los Angeles Metro, Metrolink and the Expo light rail authority.