[CASE STUDY] San Diego Association of Governments
Illustrating transportation behavior changes within a region.
StreetLight Data and Fehr & Peers teamed up to provide analytics to The San Diego Association of Governments (SANDAG), the regional planning agency in San Diego County. In 2012, SANDAG acquired the South Bay Expressway, a private toll-road running north-south along the eastern side of the region. SANDAG slashed tolls, with the primarily goal of diverting traffic away from the major interstate, I-805, to help alleviate congestion. A year later, SANDAG wanted additional analytics to help understand the impact of the toll reduction and answer the fundamental question - are drivers actually switching routes?
The StreetLight Solution
StreetLight provided “before and after” metrics, which analyzed relative shares of traffic on both roads before the toll reduction and then after the reduction had been in place for a few months. StreetLight’s metrics clearly illustrated the shift in drivers’ behavior and how it differed both spatially (e.g. northbound versus southbound trips) and temporally (e.g. weekday commuting times versus weekend activities).
Now SANDAG is better equipped with information to show the return from the major infrastructure investment.