The I-5 Widening EIS’s Incomplete Traffic Study

By now, it’s too late to defeat the proposed widening of the I-5 between the vicinity of SR 91 and I-605 in Los Angeles County. The Final Environmental Impact Statement, which is mercifully available in English, was released this summer, meaning the chance for the public to comment officially is over. Unofficially, it’s never too late to kill a project until the spades are in the ground.

The widening would take the current 6-lane stretch of road and widen it two more lanes in each direction. One of the given reasons to complete the project is because it will reduce carbon emissions. On page 162 (172 in your pdf file) of the EIS it says:

It should be noted that although traffic volumes are expected to
increase from their existing levels, the decrease in emission factors due to
improved technology and lower ambient levels would more than offset the
increase in CO emissions from increased traffic volumes.

 

However, as discussed here last week, increasing lane miles will also increase the amount of traffic on the road. The EIS/EIR for this project doesn’t take into account that the widened Route 5 will attract more traffic (and thus will create more traffic for SR 91, I-605 and the 405) than an un-widened road. The traffic study assumes that a widened I-5 will see the same increase in traffic as an-unaltered road so emissions will go down as congestion goes down.

Unfortunately, we know that not to be the case.
Decades of road widening projects across the country have proven that wider roads attract more traffic, but that knowledge has yet to find its way to an environmental study on the West Coast. The hard learned lessons of the east coast are ignored by west coast engineers, dooming us to see a repeat of their mistakes.
Again, this graphic is the actual work product of a DOT engineer in New Jersey in 2005, illustrating the reality of induced demand. Lets hope we start seeing some of that thinking here before our highway system is built out.

ALSO ON STREETSBLOG

For Goodness’ Sake, Stop Widening the 405

|
Albert Einstein says that the definition of insanity is “doing the same thing over and over again and expecting different results.” I have bad news for transportation planners at OCTA and Caltrans. You’ve gone insane. And the disease is spreading. The Orange County Transportation Authority and Caltrans are banding together for another 1950’s style environmental disaster, […]

Ten Reasons L.A.’s Mobility Plan Needs to End Road Widening

|
The City of Los Angeles is updating its primary transportation plan, something it hasn’t done since 1999. The new Mobility Plan 2035, authored by the City Planning Department (DCP), will be before the city’s Planning Commission tomorrow. There is some welcome stuff — especially in the vision statements — in the latest draft Mobility Plan. It […]

Damn the Gas Prices, Full Road Widenings Ahead

|
Despite concerns from residents living adjacent to the highway that a highway widening of Route 57 would ruin their quality of life, officials from the Orange County Transportation Authority and Caltrans will not change their plan to widen five miles of highway in Orange County.  The transportation officials pushing the project argue that reducing congestion […]