Would congestion ease under Metro's traffic improvement ballot measure?

The Los Angeles County Metropolitan Transportation Authority will finalize a plan later this week to put a sales tax increase on the November ballot to fund billions in transportation projects. 

The agency has dubbed the measure the Los Angeles County Traffic Improvement Plan, hoping it will draw support from the required two-thirds of county voters needed to approve the tax increase.

The tax revenue would fund new rail lines, rapid bus service and highway expansions, but whether it would actually improve traffic is an open question.

"Traffic relief can be many things to many people," said UCLA Professor Juan Matute. He said adding capacity with more transit and highway lanes does move more people and could improve commute times for bus riders or cyclists.

But transportation research – including a study commissioned by Metro – shows adding car lanes or taking cars off the road with more transit has minimal effect on congestion and traffic delays in crowded cities like L.A.

That's due to a well-documented phenomenon called triple convergence in which commuters who had either not made trips or did so at different times, whether via different routes or different modes of transportation, all converge on a road that has newly expanded capacity.

Metro spokeswoman Pauletta Tonilas defended the ballot measure's traffic improvement claim  — "when we look at the masses of people that are expected to move into L.A. County, that will increase congestion if we don’t do something about it," she said.

The Metro board will vote to finalize the ballot measure Thursday.

While many have dubbed the proposed measure "R2" after the successful 2008 transportation tax, the agency is still awaiting confirmation of which letter the measure would be assigned for the November ballot. Tonilas said the transit agency is pushing for an "M" designation.

"That has significance. It stands for Metro, mobility, moving," she said.