Impact of access density on number of crashes at commercial roadways

Graduation date: 2010Numerous research efforts have proven the safety benefits of access management. There are several access management techniques, including unsignalized access spacing, signalized intersection spacing, left-turn lanes, right-turn lanes, Two-Way Left-Turn lanes (TWLTLs), nontraversable median, U-turns, interchange access separation distances and so on. \ud \ud This project explores the correlation between access density and number of segment crashes per mile. Several factors are considered to influence crashes along a commercial road: access density, traffic volume, crash type, vehicle action, number of lanes, and the implement of medians and TWLTLs. \ud \ud For this effort, 40 sample sites were randomly chosen from 8 Oregon state cities. A limited exploratory analysis evaluated correlation relationships between crash incidence per mile and access density. The author investigated the access density on each side of the roadways in order to evaluate the influence of driveway on crashes that occurred during turning movements. This research indicated that there was some correlation between crashes per mile and access density. The author concludes that it is likely that average daily traffic and number of lanes may also affect the number of segment crashes per mile