Research Article Transportation Research Record 1–11 Ó National Academy of Sciences: Transportation Research Board 2019 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0361198119895237 journals.sagepub.com/home/trr Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida Adrian Sandt 1 , Haitham Al-Deek 1 , Md Imrul Kayes 1 , Patrick Blue 1 , and Valentina Gamero 1 Abstract In recent years, rectangular flashing beacons (RFBs) and other technologies have been used as wrong-way driving (WWD) countermeasures on limited access facilities. Studies have shown that these devices effectively reduce WWD, but no research has compared the financial benefits and costs of these countermeasures. Three different methodologies were used to con- duct benefit–cost analyses for RFB WWD countermeasures installed on Central Florida toll road exit ramps. The studied benefits included savings from reductions in WWD crashes, non-crash events, and injuries, whereas costs included equip- ment, installation, and maintenance costs. For the first two methodologies, the reduction in WWD crash risk (WWCR) at the RFB-equipped ramps was determined. This WWCR considered non-crash WWD events, interchange design, and traffic volumes. Different measures of effectiveness (turn-around percentage of detected wrong-way vehicles at the RFB ramps and reduction in WWD 911 calls and citations at the RFB interchanges compared with similar comparison interchanges without RFBs) were used in these two methodologies to estimate the WWCR reduction and associated savings. For the third metho- dology, the relationship between WWD crashes and non-crash events was used to determine the average savings for WWD 911 calls and citations. Before–after analyses were then conducted to determine the individual reductions in WWD 911 calls and citations. Applying these three methods resulted in life-cycle benefit–cost ratios ranging from 2.49 to 4.10 (crash savings) and from 4.77 to 7.20 (injury savings). Other agencies could use these methodologies to determine the benefits of WWD countermeasures or other technologies with limited crash data. Wrong-way driving (WWD) crashes can be severe, espe- cially on limited access facilities owing to their high travel speeds. Reducing these crashes can improve safety and operations as they often result in injuries and fatalities causing extensive lane closures and traveler delays. There are many types of WWD countermeasures available for agencies to implement, including traditional signs and pavement markings, enhanced signs and markings (such as lowered signs or reflective pavement arrows), and intelligent transportation system (ITS) technologies with detection and notification capabilities. Examples of ITS WWD countermeasures include ‘‘Wrong Way’’ signs equipped with rectangular flashing beacons (RFBs) or light-emitting diodes (LEDs), detection devices, and cam- eras. Previous studies have shown that these technologies are effective at preventing wrong-way drivers from enter- ing the mainline (1–5). However, the lack of WWD crash data makes it difficult to quantify the crash reduction and associated savings provided by these devices. In this paper, three methodologies are developed that agencies can use to determine the crash and injury sav- ings provided by ITS WWD countermeasures. The main components of these methodologies are a WWD crash risk (WWCR) reduction approach, before–after analyses using a comparison group, and examination of the over- lap between WWD crashes and non-crash events (WWD 911 calls and citations). The WWCR reduction approach was originally developed by the authors to determine the optimal deployment locations for ITS WWD counter- measures (6, 7), but it can also be used to estimate the benefits of deployed countermeasures. These methodolo- gies could be applied by any agency worldwide to 1 Department of Civil, Environmental, and Construction Engineering, University of Central Florida, Orlando, FL Corresponding Author: Address correspondence to Haitham Al-Deek: Haitham.Al-Deek@ucf.edu