New carpool lane gets support

A proposal to add high-occupancy toll lanes to the San Diego Freeway in Orange County, including a stretch of the 405 through Costa Mesa, took a step forward this week when the O.C. Transportation Authority’s board approved further environmental and engineering study of the project.

A report presented to the board found that the idea is financially viable and would help pay for the cost of the freeway expansion, which could cost as much as $2.2 billion. The board on Monday decided to explore the option more fully.

The proposal to add a general-purpose lane and a high-occupancy toll lane in each direction on the 405 between the 73 and the 605 freeways is one of several options being explored. There is already one carpool lane in each direction that would be converted into a high-occupancy toll lane, so it would create a total of two express high-occupancy toll lanes in each direction.

Such lanes are like traditional carpool lanes but are also open to those willing to pay a toll.

Adding two express lanes in each direction would significantly ease rush-hour traffic on the 405 and allow high-occupancy toll lane traffic to move at 65 mph, the report found.

About $600 million in funding for the 405 expansion is available from Measure M2 — a half-cent county sales tax that pays for transportation improvements — but that is far less than is needed for even the most modest expansion being considered.

Tolls generated would offset the difference and fully fund the project if the lanes were restricted to toll payers and vehicles with three or more passengers, according to the OCTA report.

The cheapest option being explored is to add one general-purpose lane in each direction, which would cost $1.7 billion but would generate no revenue. The most expensive is to add two express lanes in each direction and charge tolls, which would cost $2.2 billion but would generate $197 million annually — enough to support the full cost of the project.

The freeway expansion is tentatively slated to begin in 2016.