The transportation system for the western part of the United States, Silicon Valley included, was built around the private automobile. Federal and state government funds have supported the construction of thousands of miles of highways designed for the single commuter. However, a growing realization of the impact of carbon based fuels on our environment and the continued population growth in California and its resulting traffic congestion have led many communities to adopt and support alternative means of transit.
In 2011, California gas prices reached a historic high of $3.93 per gallon. Vehicle miles traveled (VMT) increased five percent for Silicon Valley residents, following four years of declining levels. This simultaneous increase in VMT per capita and gas prices runs contrary to recent trends and is likely due to the region's gradual recovery from the recession, as residents drive to work (and for pleasure) due to increased employment and rising wages. With the exception of 2009, gas prices have risen steadily each year; from 2009 to 2011statewide gas prices have increased 35 percent while VMT per capita ticked up two percent.
In 2008 the California legislature passed Senate Bill 375 which called for local governments to lessen green house gas (GHG) emissions specifically by reducing the VMT per capita. By creating higher density development, better alternatives to solo driving, and pricing both driving and parking to reflect the real, social costs of these actions, the effort to reduce VMT is an integrated strategy to reduce the GHG emissions in the state while improving public health outcomes. The Metro Transit Authority (MTA) has jurisdiction over the nine county area that includes Silicon Valley. MTA's targets for emissions reductions are a seven percent reduction by 2020 and a 15 percent reduction by 2035. The base year for the reductions is 2005. While most of the GHG reductions will come from increased integration of like alternative fuels and more efficient vehicles, reducing the overall miles traveled by single occupancy drivers should create positive social and environmental benefits for the entire region.
Over the last decade, driving alone has continued to be the predominant mode of transportation for commuters. However, since 2003, more people are utilizing other means of transportation than driving to work, leading to a three percent drop in car commuting. Those who commute on a bicycle, motorcycle, or through other means increased 1.2 percent in the eight year span. Public transit and walking grew in relative popularity as well.
Transit ridership ticked upwards 1.3 percent in 2012 after back-to-back declines in 2010 and 2011. Compared to a decade ago, transit usage has dropped off precipitously; per capita transit ridership declined 18 percent from 2002 to 2012, dropping from a high of 33.5 to 27.5 rides per person. In the aftermath of both of the decade's recessions, transit ridership dipped in the subsequent three years before recovering slowly.
The San Francisco peninsula is increasingly integrated. Silicon Valley continues to see a robust flow of commuters within the two counties as well as between the region and San Francisco. In 2011, a quarter of peninsula commuters lived in San Francisco and commuted to Silicon Valley, while over a third lived in Silicon Valley and worked in San Francisco.