Photo by Damien [Phototrend.fr] on Flickr.

The Metrobuses on 16th Street NW carry half of all traffic during peak hours, using only 3% of the vehicles. But buses share street space with cars. If they had their own lane, WMATA could save close to $8 million a year.

It goes without saying that it costs money to run buses. But it’s less obvious that the speed of a bus is directly related to the cost of providing the service. Simply put, if we double the speed of a bus, we can provide the same service for half the cost. Or for the same cost, we can provide twice as much service.

Bus lanes are one of the tools we can use to make buses move faster and be more efficient. On 16th Street, since buses carry such a large proportion of the users of the street, bus lanes are a perfect tool. Talk of a bus lane has even made it into the mayoral race, though it’s not entirely clear how strongly each of the candidates would support it.

Saving time

WMATA’s Priority Corridor Network study looked at several corridors, including 16th Street. It determined that, if nothing changed, by 2030 a bus would take about 40 minutes to get from Silver Spring to McPherson Square. However, if there were a bus lane, buses in 2030 would be able to cover the same distance in just over 20 minutes.

That means a bus lane would cut transit travel time in half. It would also mean that a bus rider could cover the distance between Silver Spring and downtown DC faster than a motorist, which would make transit more competitive.

But even with one fewer lane, estimates show that motorists’ travel time wouldn’t increase significantly. With the bus lanes, a 2030 car trip would be 4 minutes longer than without them.

Saving money

Right now, it costs $16.1 million dollars each year to run the 16th Street buses, the S1, S2, S4, and S9. Bus lanes could cut those costs in half. And that means there’s an opportunity cost of not installing the lanes. That cost is about $8 million dollars a year.

Of course, because the 16th Street Line is a regional route, that money wouldn’t all go back to the District’s coffers. It would go back to all the jurisdictions. DC would save about $3.3 million, Prince George’s would save about $1.4 million, and Montgomery and Fairfax would save about $1.1 million each.

The District should support bus lanes on 16th Street not only because it’s good for transit users. They should also support the bus lanes because they represent a more efficient use of the space (remember, buses move 50% of the people on 16th Street already). But just as importantly, the District should support bus lanes because there’s a real monetary cost to the region for not supporting them.