Adrian Sandt

Wrong-Way Driving: Multifactor Risk-Based Model for Florida Interstates and Toll Facilities

Wrong-way driving (WWD) is one of the most dangerous driver errors or behaviors on limited access facilities. Previous studies focused on analyzing WWD crashes but discovered that WWD crashes were extremely rare. Using WWD 911 calls and WWD citations, which occur much more frequently than WWD crashes, to help predict WWD risk allows roadway agencies to be proactive and implement WWD countermeasures at problem areas instead of waiting for serious WWD crashes to occur. This study developed a model to determine WWD risk according to WWD crashes, citations, and 911 calls. For the development of this novel model, a market basket analysis was used to determine the overlap between the three WWD data sets (crashes, 911 calls, and citations for the years 2011 and 2012 on Florida Interstates and toll roads). The independent WWD events were then used to develop a generalized Poisson regression model that allowed the WWD 911 calls, citations, and crash frequencies to be converted to WWD risk values. WWD risk densities were also calculated by using either vehicle miles traveled or roadway length to consider exposure. The counties and roadways were then ranked with respect to WWD risk values and densities; these rankings indicated that Miami–Dade was a problematic county because it was ranked highest by WWD risk value and its nine Interstates or toll roads were ranked in the top 15 by WWD risk density. The developed model and macroscopic rankings are very useful to help identify counties and roadways where WWD countermeasures should be implemented.

Evaluation of Conditional Transit Signal Priority Technology for Regional Implementation

This research evaluated the implementation of transit signal priority (TSP) on a test corridor along International Drive in Orlando, Florida, to see whether the implementation was successful and justified expansion to a regional implementation of TSP for bus tie-ins to the new regional SunRail commuter rail in Central Florida. TSP is a technology that provides preferential treatment to buses at signalized intersections. This research demonstrated the effectiveness of TSP in improving bus corridor travel time in a simulated environment by using real-world data for the International Drive corridor. Evaluation was conducted with microsimulation to compare unconditional and conditional TSP with the no TSP scenario. This evaluation looked at performance metrics (for buses and all vehicles), including average speed profiles, average travel times, average number of stops, and crossing street delay. Different conditional TSP scenarios of activating TSP when a bus is 3 or 5 min behind schedule were considered. The simulation demonstrated that conditional TSP significantly improved bus travel times with little effect on crossing street delays. Unconditional TSP resulted in significant crossing street delays at some intersections with only minor improvement to bus travel time compared with both conditional TSP scenarios. The results also showed that using TSP technology reduced the environmental emissions in the International Drive corridor. With a benefit–cost ratio of 7.92 in the International Drive corridor, conditional TSP 3 min behind schedule was determined to be the most beneficial and practical TSP scenario for real-world implementation at corridor and regional levels.

Identifying Wrong-Way Driving Hotspots by Modeling Crash Risk and Assessing Duration of Wrong-Way Driving Events

Because wrong-way driving (WWD) crashes are often severe, it is important for transportation agencies to identify WWD hotspot segments appropriate for potential implementation of advanced WWD countermeasures. Two approaches to identify these hotspot segments were developed and applied to a case study of limited-access highways in Central Florida. The first approach used a Poisson regression model that predicted the number of WWD crashes in a roadway segment based on WWD citations, 911 calls, traffic volumes, and interchange designs. Combining this predicted crash value with the actual number of WWD crashes in the segment gave the WWD crash risk of the segment. Ranking roadway segments by WWD crash risk provided agencies with an understanding of which segments had high WWD crash frequencies and high potential for future WWD crashes. This approach was previously applied to South Florida; the research presented here extended this approach to Central Florida. The second approach was based on operational data collected in traffic management centers and could be used if accurate WWD 911 and citation data with GPS location were not available or as a supplement to the first approach. The approach identified and ranked WWD hotspots on the basis of the reported duration of WWD events. In Central Florida, the results of the two approaches agreed with each other and were used by agencies to decide where to implement advanced WWD countermeasures. Together, these approaches can help transportation agencies determine regional WWD hotspots and cooperate to implement advanced WWD countermeasures at these locations.

Wrong-Way Driving Prevention: Incident Survey Results and Planned Countermeasure Implementation in Florida

Wrong-way driving (WWD) crashes are rare on Central Florida roadways. However, WWD is a severe hazard, especially on high-speed limited access roadways. This research developed the first driver survey to obtain details about unreported WWD events on Central Florida toll roads and freeways. This phone survey asked participants about WWD events witnessed either by the participant or by a family member, friend, or acquaintance. The 400 completed surveys showed that State Road 408 (SR-408) and Floridas turnpike (SR-91) experienced the most WWD events. Fourteen percent of the WWD events resulted in a crash, and only 10% of the WWD events witnessed by participants were reported to law enforcement or roadway agencies, even though 50% of the events caused the survey participants to feel a high risk of danger. These results show that WWD is more frequent than indicated by crashes or 911 calls. On the basis of these results, the Central Florida Expressway Authority (formerly known as the Orlando–Orange County Expressway Authority) is pilot testing and evaluating the use of rapid rectangular flashing beacons (RRFBs) as a WWD countermeasure. This test will be the first use of RRFBs to combat WWD. Elsewhere, Floridas Turnpike Enterprise is installing flashing “Wrong Way” signs along the Homestead Extension (SR-821) and Sawgrass Expressway (SR-869) in South Florida, and the Florida Department of Transportation is implementing a variety of WWD countermeasures at I-10 ramps in Tallahassee in North Florida.

Regional Evaluation of Bus Rapid Transit With and Without Transit Signal Priority

This paper evaluates the performance of various bus rapid transit (BRT) scenarios with and without transit signal priority (TSP) in improving speeds and reducing travel times and delays on a real-life corridor along International Drive (I-Drive) in Orlando, Florida. This corridor is crucial for the regional economic prosperity of Central Florida. Microsimulation and statistical analysis were used to develop BRT models. The developed models used a variety of data to determine several measures of effectiveness for all vehicles and for buses only. Simulation results showed that TSP and BRT scenarios were effective in reducing travel times (up to 26%) and delays (up to 64%), as well as increasing the speed (up to 47%), compared with the base scenario. The most effective scenarios were achieved by combining BRT and TSP. Unconditional TSP scenarios produced significant crossing street delays, especially at high-traffic intersections, indicating that these scenarios are impractical for implementation and lead one to use the conditional TSP. The developed models with real-life data input are able to predict how proposed enhancements change the studied measures of effectiveness. The BRT models presented in this paper can be used for further sensitivity analysis on a larger regional network in the upcoming regional expansion of the transit system in Central Florida. Since this study demonstrated the operational functionality and effectiveness of BRT and TSP systems in this critical corridor in Central Florida, these systems’ accomplishments can be expanded throughout the state of Florida to provide greater benefits to transit passengers.

A technical note on evaluating the effectiveness of bus rapid transit with transit signal priority

ABSTRACT Transit Signal Priority (TSP) and Bus Rapid Transit (BRT) are innovative Intelligent Transportation System (ITS) tools that can reduce travel times for buses. Combining TSP and BRT can significantly improve bus travel, but can negatively impact network traffic operations. Although TSP has been implemented worldwide, few previous studies holistically examined the effects of using various conditional and unconditional TSP strategies with or without a BRT system. This research simulates multiple TSP and BRT combination scenarios to understand their impact on traffic operations, including crossing street traffic. A test bed along International Drive (I-Drive) in Orlando, Florida, was chosen as the simulation area. Field data collected for this test bed, which included traffic volumes, bus travel times, and traffic signal control data, were used to develop, calibrate, and validate the simulation model. Results showed that BRT with Conditional TSP 3 minutes behind significantly improved travel times, average speed, and average total delay per vehicle for the main through movements compared with no BRT or TSP, with only minor effects on crossing street delays. BRT with Unconditional TSP resulted in significant crossing street delays, especially at major intersections with high traffic demand, indicating that this scenario is impractical for implementation. The simulation suggests that BRT and TSP will be most effective when used in areas where crossing street volumes are low. However, it is unknown how these ITS tools affect pedestrian traffic. Using optimization methods can determine the best strategy to balance transit and pedestrian traffic.

Evaluating Wrong-Way Driving Characteristics, Countermeasures, and Alert Dissemination Methods through Driver and Law Enforcement Surveys

Wrong-way driving (WWD) on limited-access highways is a serious driver error that could be fatal for both the wrong-way driver and right-way drivers. Agencies and law enforcement officers (LEOs) can spend valuable time and resources responding to WWD events. A survey of 247 LEOs found that despite being dispatched multiple times per year in response to WWD, most issue fewer than one WWD citation per year. In the survey, LEOs also gave their perspectives on the characteristics of WWD events and the influences behind WWD. Agencies typically use dynamic message signs (DMS) for notifying right-way drivers of WWD events, but little research has considered solutions that are less costly and potentially farther-reaching. A survey of 900 Florida toll-road drivers found that drivers rely on navigation devices, apps, or both, significantly more than DMS for traveler information. Drivers were receptive to receiving WWD alerts through navigation services and indicated that they would react to WWD events in a way that is beneficial to highway safety. Crowdsourcing technologies were considered to generate WWD information and quickly disseminate alerts to drivers and officers. Additional survey questions answered by a combined group of 2,052 drivers, LEOs, and agency officials determined that among advanced WWD countermeasures, most preferred two sets of “Wrong Way” signs equipped with rectangular flashing beacons over one set of signs with light emitting diodes. Combining advanced countermeasures with innovative right-way driver notification methods could enhance law enforcement efficiency, reduce WWD crashes, and provide safer conditions for both drivers and officers.

Analysis of Performance Data Collected from Two Wrong-Way Driving Advanced Technology Countermeasures and Results of Countermeasures Stakeholder Surveys

Wrong-way driving (WWD) often leads to severe collisions that cause serious injuries and deaths. Conventional “Wrong Way” signs can reduce WWD events, but can be insufficient in some cases. In areas with many WWD events, transportation agencies can be proactive by considering the use of countermeasures with advanced technologies to actively warn motorists of WWD violations. This paper analyzes recent performance data collected from two types of advanced technology WWD countermeasures implemented in Florida: light-emitting diode (LED) signs in South Florida and rectangular flashing beacon (RFB) signs in Central Florida. The 17 LED sites experienced a 38% reduction in WWD citations and 911 calls after the signs were installed. Images taken by the on-site cameras were examined to see how many vehicles turned around for both the RFB and LED treatment sites. Over 77% of the 170-detected wrong-way vehicles self-corrected their wrong-way movement at the RFB sites (each with two sets of signs and multiple cameras) and 14% self-corrected at the LED sites (each with one set of signs and one camera). Surveys were also conducted regarding these two WWD countermeasures. More than 73% of the 2,052 respondents preferred RFBs over LEDs, mainly due to the double set of RFB signs and their flashing pattern. The performance and survey results show that both the LEDs and RFBs have effectively reduced WWD movements. However, modifications could be made to both countermeasures to improve their detection ability and make wrong-way drivers more likely to turn around.

A Wrong-Way Driving Crash Risk Reduction Approach for Cost-Effective Installation of Advanced Technology Wrong-Way Driving Countermeasures

Wrong-way driving (WWD) is hazardous on high-speed limited access facilities. Traditional signage and pavement markings will not always prevent intoxicated or confused drivers from entering these facilities the wrong way. To better alert wrong-way drivers, agencies can consider WWD countermeasures equipped with advanced technologies (including warning lights and detection devices) on exit ramps. However, these countermeasures can be expensive for agencies to install on entire roadways or corridors. This paper develops an innovative WWD crash risk (WWCR) reduction approach consisting of a WWCR segment model and an optimization algorithm that can be used to help agencies decide where to install WWD countermeasures. The approach examines segments of limited access facilities to determine the interchanges where advanced technology WWD countermeasures will provide the greatest reduction in WWCR based on an agency’s available resources. A hypothetical example application of this approach is shown for the Central Florida Expressway Authority toll road network. This example shows how the WWCR reduction approach can help agencies identify the optimal investment level and high-risk locations. It also shows how the optimization algorithm can provide significant cost savings compared with equipping entire roadway segments (57% savings) or corridors (83% savings). Agencies can customize the algorithm by adding constraints to represent various scenarios and make the algorithm applicable for networks ranging from single roadways to statewide systems. This WWCR reduction approach could be utilized by agencies nationwide to help them save resources and prioritize investment.

Wrong-Way Driving: A Regional Transportation Systems Management and Operations Approach to a Regional Problem

Wrong-way driving (WWD) has been problematic on United States highways for decades despite its rare occurrence. Since WWD crashes are rare, recent researchers have studied WWD non-crash events such as WWD 911 calls and WWD citations to understand the overall nature and trend of WWD. This paper demonstrates the regional nature of the WWD problem and proposes regional transportation systems management and operations (TSM&O) solutions to combat this problem. Specifically, it was found that 11% of all WWD multi-data events (e.g., multiple 911 calls for the same WWD event) involved travel from one county to another. Additionally, 30% of all WWD single-data and multi-data events occurred at or near interchanges between two limited access highways in counties with multiple operating agencies. This indicates that a significant proportion of WWD events could potentially travel from one limited access facility to another. Moreover, 28% of WWD events occurred on limited access facilities shared by multiple operating agencies. To emphasize the regional nature of WWD, this paper determined the vulnerable demographic groups in different regions of Florida by developing WWD crash and citation prediction models. The models’ findings indicate that certain demographic groups (e.g., elderly drivers) increase WWD risk. The models’ results can be used to improve driver education and increase law enforcement presence in high risk WWD locations. Regional TSM&O solutions, such as coordination and communication among agencies and traffic management centers (TMCs), law enforcement co-location with TMCs, and strengthening statewide TSM&O programs to manage WWD events are also proposed.