Traffic Congestion

How Are We Doing?

The traffic congestion indicator measures the impact of travel time on San Diego commuters due to the increase of vehicles on the road at a particular time, producing slower than expected travel times. Congestion affects the cost to each individual commuter through increased fuel use and lost work hours. The consequences of road traffic congestion affect society as a whole through its impacts on speed and travel time, cost and the environment.

Traffic congestion received a thumbs down because vehicle hours of delay per commuter continued to increase. San Diego commuters in 2019 spent more than 8 hours on the freeways due to delays, nearly an hour more than in 2016. San Diegans travel more freeway vehicle miles per person 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 2018 to 2019

There are many ways to measure traffic congestion - especially because it varies depending on traffic incidents, time of day, weather, work zones, special events, traffic control, and bottlenecks. How reliable the system is to get a person from point A to point B depends on the combination of all of these factors. One metric used to measure traffic congestion is the change in freeway usage across years, measured in vehicle miles traveled (VMT). San Diego freeway VMT per capita is about the same as Orange County, and above the state average. Other Southern California counties, such as Riverside and San Bernardino County, had higher per capita freeway VMT from 2013 to 2018. However, this gap has diminished significantly in recent years, such that in 2019, the per capita freeway VMT in San Diego, Riverside, and San Bernardino County were very similar.

San Diego and Orange County tracked together in total freeway miles traveled in the past eight years, which was much lower than Los Angeles County. Los Angeles County is about the same size (4,751 square miles) as San Diego County (4,500 square miles), but with three times the population. Riverside County, about twice the size of San Diego County (7,303 square miles), and San Bernardino County, three times larger than San Diego County (20,105 square miles), had similar total freeway miles as San Diego County, despite the larger land area.

Freeway VMT also varies by day, night, weekdays, and weekends. Weekday peak hours are defined as 6 to 10 am in the morning and 3 to 7 pm in the afternoon and early evening. Miles traveled during peak hours consistently made up approximately 35% of total freeway miles over the past eight years, while miles traveled during weekday non-peak hours, weekends, and holidays made up the larger and increasing portion of total VMT.

Another way to measure traffic congestion is the peak hour delay. Tracking the weekday peak hour delay measures how the system is managing the demand of and changes needed to improve the quality of access to work or other activities. Due to delays during morning and afternoon commute times, San Diego County commuters in 2019 spent more than 8 extra hours  on the freeways, that is nearly an hour more than what was reported in 2016. The hour of delay reflects "stop-and-go" severe freeway congestion with vehicle speeds averaging below 35 miles per hour and the afternoon commute hour delay being more severe than the morning commute hour delay.

Why is Traffic Congestion Important?

High quality of life means the region boasts a thriving economy, a healthy environment, and is an equitable place for all San Diegans to grow and prosper.

  • Environment: Traffic congestion has negative impacts on the environment arising from decreased air quality and waste of fuel, increasing costs to both individuals and businesses, and increasing greenhouse gas emissions affecting the climate in the long-term. 
  • Economy: Traffic congestion has negative impacts on individuals and the economy. Fuel waste from traffic congestion increases costs to individuals and businesses through increased travel times, costs, and lost productivity. Traffic congestion can indicate a thriving regional economy and in the San Diego border region, traffic congestion increases the flow of goods and services in both directions on roads. However, the focus on trucks and cars on roads has negative environmental implications. The Otay Mesa East project added 20 new lanes and separated cargo from passenger traffic in 2017 as a short-term effort to relieve congestion, but in the long run will serve to increase road flow. The San Diego Regional Chamber of Commerce therefore advocates for the re-establishment of a functional cross-border rail system which would significantly improve multimodality and reduce road traffic congestion.
  • Equity: Although San Diego does not rank among the top 10 urban areas in the U.S. for traffic congestion, congested roads decrease air quality, especially in communities in the immediate vicinity. Many of these highly exposed communities are also communities with high concentrations of poverty. 

Regional Response


SANDAG’s 2015 Regional Plan includes an intermodal transit system in San Ysidro (2014 San Ysidro Intermodal Transportation Center final report), improved and new rail connections throughout the region, as well as congestion pricing to motivate multi-model uses.


The County of San Diego’s Active Transportation Plan was approved by the Board of Supervisors in 2018. Increasing biking lanes and walking trails, as well as the safety of non-motorized vehicle users, improves public health and enhances regional efforts to meet greenhouse gas emission goals.


Circulate San Diego in partnership with Rady Children’s Hospital and California Office of Traffic Safety, launched online educational resources and activities to promote safe walking trails and biking lanes.

U.S.-Mexico Border Region

For personal vehicles, there are three land-based ports of entry from Mexico into the United States within San Diego County: Otay Mesa, San Ysidro, and Tecate. In 2019, the total number of northbound personal vehicle crossings at all three ports of entry was approximately 22 million, 3% lower than that in 2018. The San Ysidro port of entry had close to 15 million crossings, in 2019, the highest number in the past ten years. Also in 2019, the San Ysidro port of entry had the highest number of personal vehicle crossings of all ports of entry into the United States, followed by the El Paso port of entry in Texas with 11 million crossings, and the Otay Mesa port of entry with 6.5 million crossings. The Otay Mesa port of entry had fewer crossings in 2019 compared to 2018, with a decrease of 15%.

For freight trucks, there are two land-based ports of entry from Mexico into the United States within San Diego County: Otay Mesa and Tecate. In 2019, the total number of northbound freight truck crossings, not including privately owned pick-up trucks, at both San Diego County ports of entry were approximately 1 million, similar to that of 2018. More than 95% of the freight truck crossings occured at the Otay Mesa port of entry. The Otay Mesa port of entry was recognized as the second busiest port of entry in 2019 for freight truck crossings along the U.S.-Mexico border following the Laredo port of entry in Texas.

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.