Pedestrian Engineering and Enforcement at Signalized Intersections

Principal Investigator(s):

Nichole Morris, HumanFIRST Lab Director, Mechanical Engineering


Project summary:

Pedestrian deaths are at a 30-year high nationally, accounting for 16 percent of total deaths in 2018 and far exceeding the previous decade of 12 percent, a trend mirrored in Minnesota. Previous research found an increase in local and citywide yielding at unsignalized crosswalks following an engineering and high-visibility enforcement program in Saint Paul, Minnesota. This study examined a modified engineering-focused (i.e., without enforcement) program expanded to both unsignalized and signalized intersections across the Twin Cities. The six-month study found modest improvements in yielding from baseline to treatment end (48.1 percent to 65.5 percent in Saint Paul and 19.8 percent to 38.8 percent in Minneapolis) at unsignalized engineering treatment sites but no improvements at generalization sites. No significant improvements in left- or right-turning yielding by drivers in Saint Paul were found at treated signalized intersections--but given that yielding was significantly worse at generalization sites over time, there may be some evidence that treatments mitigated performance declines among Saint Paul drivers during the study period. Yielding improvements at signalized treatment sites were more pronounced for only right-turning drivers in Minneapolis, but generalization sites showed no improvement or even worsened over time. Overall, study results suggested no shift in driving culture in either city--as found with the previous study using police enforcement--but found some evidence of local, site-specific changes in driver yielding behavior at treatment locations.

Project details: