Big changes coming to the 55

Beginning today, using the carpool lane will change forever on the Costa Mesa Freeway as part of a program began last year on the 22 Freeway. According to the OC Register:

Beginning Tuesday, drivers of vehicles carrying two or more people on the 55 freeway will be able to enter or leave the carpool lanes where they choose -– part of a plan to overhaul the carpool system in the county. A 5.5-mile stretch on the 55, between the 17th Street overcrossing and the 91 Freeway interchange, will become "continuous-access." ... Starting  Tuesday, crews will replace the double, solid-yellow lines that separate the car-pool lanes from the regular ones with temporary dotted striping. Permanent striping is scheduled to begin the week of Aug. 10 and is expected to be complete at the end of August.

The Times' My-Thuan Tran reports the advantages:

Allowing drivers to go in and out of carpool lanes freely results in fewer and less severe accidents, according to a 2007 study by UC Berkeley transportation researchers. The report found that using yellow lines to restrict access resulted in 3.6 collisions per mile compared with 3.2 collisions per mile for free access freeways. [The Orange County Transportation Authority] and the California Department of Transportation decided to convert the lanes after a successful experiment in December 2006 with unrestricted carpool lanes on the 22 Freeway. An OCTA-commissioned survey in 2007 also found that 71% of drivers on the 22 Freeway preferred unrestricted carpool lanes.

Comments

[Diane Sbardellati]

I've experienced this type of carpool lane on freeways in Washington State and found it to be easier and safer. The flow of traffic is less impacted, and there is far less panic as the driver chooses the point of entry and exit. I was hoping to see this here in Southern CA.

[BOB2]

The UC Berkeley study was on the unlimited access to the HOV lane on the State Route 22 was rightly criticized for reaching a conclusion with too few data points and conducted over too short a period to prove anything. Numerous studies of accident rates with unlimited access mixed flow lanes shows them to have a higher likelihood of accidents due to the effects of additional weaving, and more weaving also results in more congestion.

Repeated studies of HOV lane safety over the last twenty years has consistently shown a lower overall accident rate on limited access HOV than on the adjacent mixed flow lanes. Do we make public highway safety policy based on the flimsy N=1 study, or on the preponderence of evidence? In California we appear to make our decision based upon the study that justifies the predetermined political decision.

Was politics on this issue the reason why Caltran District 12 put pressure on its own staff who came to different conclusions about the benefits of unlimited access HOV lanes?