Do New Housing Developments Increase Traffic? An Analysis of Cupertino’s Current Housing Cycle

Increased traffic due to new residential developments is often touted as a reason by Cupertino citizens to oppose new housing developments in the city. In this paper, we endeavor to find whether this argument is supported by the data.

We measured the net change in car trips generated from a dataset of 22 projects in Cupertino’s current housing cycle using trip rates from the ITE’s 10th edition of the Trip Generation Manual. From this cycle’s mix of projects,we found that there is an expected net reduction of 1143 in trips from new housing developments across the city, as well as a net reduction of 3814, and 124 along major corridors Stevens Creek and De Anza Boulevard respectively. Only along Foothill Boulevard was there an expected increase of 256 trips.

Our findings challenge, for Cupertino’s specific case, the traditionally-held view that new housing developments increase traffic, as new projects in Cupertino usually replace higher-traffic office and commercial sites. Our findings also provide complementary evidence to existing research that retail centers increase car traffic.