The lesson of the I-405 widening project that birthed meme-worthy events like "Carmageddon": widening a freeway won't reduce congestion for long, if ever.

Five years after the completion of a northbound carpool lane on Interstate 405 in Los Angeles, built at a cost of $1 billion, traffic has only gotten worse.
"Since then, average northbound drive times through the Sepulveda Pass have increased at all hours of the day," reports Elijah Chiland, citing data from traffic analyst Inrix.
The project has delivered poor results in terms of congestion mitigation since it opened, so this latest news is only the most recent bad news for drivers who travel the Sepulveda Pass between the San Fernando Valley and the Westside of Los Angeles. The Los Angeles County Metropolitan Transportation Authority promised a 37 percent reduction in overall hours of delay with the project as compared to a scenario that never built the project.
But broken promises and congestion are probably the least of the concerns associated with the freeway widening project. "A 2015 policy brief from the National Center for Sustainable Transportation notes that expanding freeways is likely to result in a long-term increase in both greenhouse gas emissions and the number of miles driven in a given area," according to Chiland.
FULL STORY: Five years after Sepulveda Pass widening, travel times on the 405 keep getting worse

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