Date of this Version



connected vehicles (CV), dedicated short range communication (DSRC), dilemma zone, automated traffic signal performance measures, high-resolution controller event data, green extension, heavy trucks, probability of stopping.


The rate of fatalities at signalized intersections involving heavy vehicles is nearly five times higher than for passenger vehicles in the US. Previous studies in the US have found that heavy vehicles are twice as likely to violate a red light compared with passenger vehicles. Current technologies leverage setback detection to extend green time for a particular phase and are based upon typical deceleration rates for passenger cars. Furthermore, dilemma zone detectors are not effective when the max out time expires and forces the onset of yellow. This study proposes the use of connected vehicle (CV) technology to trigger force gap out (FGO) before a vehicle is expected to arrive within the dilemma zone limit at max out time. The method leverages position data from basic safety messages (BSMs) to map-match virtual waypoints located up to 1,050 ft in advance of the stop bar. For a 55 mph approach, field tests determined that using a 6 ft waypoint radius at 50 ft spacings would be sufficient to match 95% of BSM data within a 5% lag threshold of 0.59 s. The study estimates that FGOs reduce dilemma zone incursions by 34% for one approach and had no impact for the other. For both approaches, the total dilemma zone incursions decreased from 310 to 225. Although virtual waypoints were used for evaluating FGO, the study concludes by recommending that trajectory-based processing logic be incorporated into controllers for more robust support of dilemma zone and other emerging CV applications.


This document is the preprint version of TRB Paper No. 20-02403, submitted on August 1, 2019 for the 99th Annual Meeting of the Transportation Research Board of the National Academies held on January 12–16, 2020 in Washington, DC. The paper was presented on January 14, 2020. The paper was subsequently revised to respond to review comments in February 2020 and published on April 9, 2020. The citation for the published manuscript in the Transportation Research Record is shown below.

Li, H., Platte, T., Mathew, J., Smith, W. B., Saldivar-Carranza, E., & Bullock, D. M. (2020). Using connected vehicle data to reassess dilemma zone performance of heavy vehicles. Transportation Research Record, 2674(5), 305–314.