| Title | Safety Evaluation of Flashing Yellow Arrow at Signalized Intersections |
|---|---|
| Record ID | 78454 |
| Personal Name Creator |
Srinivasan, Raghavan; Lan, Bo; Carter, Daniel; Smith, Sarah; Signor, Kari |
| Personal Name Contributor |
Amjadi, Roya |
| Corporate Creator | VHB/Vanasse Hangen Brustlin, Inc.; University of North Carolina. Highway Safety Research Center |
| Corporate Contributor |
United States. Federal Highway Administration. Office of Safety Research and Development |
| Publisher | United States. Department of Transportation. Federal Highway Administration |
| Publication Date | 20200801 |
| Language | English |
| Abstract | This study evaluated the safety effect of the flashing yellow arrow (FYA) treatment at signalized intersections. The major objective of this strategy is to reduce the frequency of left-turn (LT) crashes, especially those that involve a collision between left turns and vehicles traveling straight through from the opposite direction. The project team conducted an empirical Bayes before–after analysis of installations in Nevada, North Carolina, Oklahoma, and Oregon. The treatments were divided into seven categories depending on the phasing system in the before and after periods, number of roads where FYAs were implemented, and number of legs at each intersection. The first five categories involved permissive or protected-permissive phasing in the before period. Intersections in these five treatment categories experienced a reduction in the primary target crashes under consideration: LT crashes and left-turn-with-opposing-through (LTOT) crashes at the intersection level. The reduction ranged from 15 to 50 percent depending on the treatment category. Intersections in categories 6 and 7 had at least one protected LT phase in the before period, and after phasing had an FYA protected-permissive LT phase without time-of-day operation (category 6) and with time-of-day operation (category 7). Consistent with results from previous studies, these intersections experienced an increase in LT and LTOT crashes. The B/C ratios for categories 1–5 ranged from 56:1 to 144:1. |
| Rosap ID | dot:51750 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/51750 |
| TRT Terms | Technical reports; Intersections; Arrows; Safety analysis; Crash modification factors; Safety factors; Turning lanes |
| Geographical Coverage |
United States |
| TRIS Online Accession No |
1754219 |
| Contract Number | DTFH61-13-D-0001 |
| Report Number | FHWA-HRT-19-036 |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/78000/78400/78454/FHWA-HRT-19-036.pdf |
| Alternative URL | https://www.fhwa.dot.gov/publications/research/safety/19036/19036.pdf |
| Format | |
| Database | NTL Digital Repository |