Traffic & Congestion

How Are We Doing?

Vehicle miles traveled and hours of delay received a thumbs-down because vehicle hours of delay per commuter continued to increase. Commuters in 2018 spent more than 8 hours extra on the freeways, nearly an hour more than in 2016. San Diegans travel more freeway vehicle miles annually than the state average and other major urban counties. Want to know more about what we're measuring?

thumbs down

Worsened more than 1 percent from 2017 to 2018

Data Source: California Department of Transportation Performance Measurement System (PeMS) 

San Diego freeway vehicle miles traveled (VMT) per person is about the same as in Orange County, and above the state average.

Data Source: California Department of Transportation Performance Measurement System (PeMS) 

San Diego and Orange counties track together in total miles traveled, which is much lower than LA County. LA County is about the same size (4,751 square miles) as San Diego County (4,500 square miles) with three times the population of San Diego.

Data Source: California Department of Transportation Performance Measurement System (PeMS)

San Diego commuters in 2018 spent more than 8 hours extra on the freeways due to delays during morning and afternoon commute hours, nearly an hour more than in 2016. The hour of delay reflects "stop-and-go" severe freeway congestion when the vehicle speed is below 35 miles per hour on the freeway.

Why is it Important?

High quality of life means a clean environment, a thriving economy, and an equitable place for all to enjoy.

  • When hours of delay increase, more fuel is used and the cost of transportation energy for households increase. When the price of gasoline is also high, the proportion of income used for transportation energy will increase and affect low-income families more than affluent families. As suggested by the Brookings Institute, low-income workers also tend to drive greater distances to reach their workplace. Another effect of increased fuel use is increased greenhouse gases and increased local air pollutants, which impacts air quality and affects vulnerable populations disproportionately.
  • According to the 2017 American Community Survey, 85% of the labor force in San Diego County travels to work by car, truck, or van. 76% of the labor force drives alone.
  • Reducing VMT and hours of delay can help the economy and improve neighborhood sustainability. Research published in the Cities Journal show walkability has a positive impact on housing valuations, crime, and foreclosure rates. 

Regional Response


Vehicle miles traveled (VMT) produce the largest component of greenhouse gases in our cities. Policies to reduce VMT help avoid greenhouse gas emissions, conserve energy and reduce air pollution at ground level. Climate action plans typically include a variety of measures to help reduce VMT such as promoting carpooling, biking and public transportation.


VMT can be reduced by linking multifamily developments to transit priority areas, with improved connections and frequencies of transit as well as improved pedestrian and bicycle facilities. Adopted in 2016, San Diego’s Affordable Homes Bonus Program reported early success in 2017 with increased applications for development of new multifamily housing with increased affordable units. In exchange for additional affordable units, developers are allowed greater unit density and relief from off-street parking requirements in areas near transit systems.

U.S.-Mexico Border Region

Data Source: U.S. Department of Transportation, Border Crossing/Entry Data, 2019

There are three land-based ports of entry from Mexico to the United States in San Diego County: Otay Mesa, San Ysidro and Tecate. In 2018, San Ysidro had over 14 and a half million northbound personal vehicle crossings, the highest of all ports of entry in the United States. Otay Mesa, with just below 8 million personal vehicle crossings, was the third busiest in the nation.

What Are We Measuring?

We have measured annual change in freeway miles driven per capita and total freeway miles driven in select counties since 2012. For the impact of traffic congestions during rush hour, we have measured the annual hour of delay per commuter during morning (6 to 10 a.m.) and afternoon (3 to 7 p.m.) commuter hour since 2006. We track northbound personal vehicle border crossings into the U.S through the San Ysidro, Otay Mesa and Tecate ports of entry. Learn more about the data.