Past projects

Pedestrian traffic signal violations: Safety, design, and operational implications

Utah Department of Transportation (UDOT), 2020–2023, PI with co-PI Michelle Mekker

Pedestrian injuries and fatalities are increasing nationally and in Utah. Intersections are of particular concern, given potential conflicts when crossing the street. Based on Utah crash reports, pedestrian behaviors may play a role in around 50% of pedestrian crashes, including: crossing outside of the crosswalk and/or crossing against opposing motor vehicle traffic. There is limited research about where or when these behaviors may be more common (e.g., near alcohol establishments, nighttime, low traffic volumes). This research project fills this gap by measuring pedestrian signal violations at a variety of locations, analyzing factors and characteristics contributing to greater violation rates, and identifying potential design and operational treatments (and educational or enforcement initiatives) to improve pedestrian safety.

  • Singleton, P., Mekker, M., & Boyer, S. (2023). Pedestrian traffic signal violations: Safety, design, and operational implications (UT-23.10). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/68345

Extending functional classification to active modes of transport

Utah Department of Transportation (UDOT), 2021–2022, USU PI as sub to Alta Planning + Design

Traditional methods of functionally classifying roads focus on motor vehicles and often produce large busy arterials that separate neighborhoods and discourage walking and bicycling. This research project constructs an alternative functional classification system specific to active transportation modes. It takes into consideration trip distances, directness, and new big data sources of travel behavior information. Results can help UDOT prioritize active transportation investment projects that are likely to have the greatest impact on walking and bicycling.

  • Wasserman, D., Young, G., Foster, D., & Singleton, P. A. (2022). Mode shift potential evaluations using desire lines & connections to active functional classification systems (UT-22.20). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/65553
  • Young, G., Wasserman, D., Foster, D., Singleton, P. A., & Tomlin, S. (2023). Evaluating segment-level active mode shift potential using desire lines. Transportation Research Record: Journal of the Transportation Research Board. https://doi.org/10.1177/03611981231175155

Active transportation facilities in canal corridors

Utah Department of Transportation (UDOT), 2020–2022, PI with co-PI Alfonso Torres

Active transportation facilities like trails provide economic and public health benefits. Canals offer potential opportunities for trails as they are existing linear facilities, have minimal grades, and often connect communities and towns. There are various potential benefits for canal companies to consider, but there are also concerns related to liability, cost, etc. There is a need to document the potential benefits and tradeoffs of various options for canal trails, as well as example case studies. This research identifies appropriate cases and where accommodating active transportation facilities in canal corridors could be beneficial to all parties involved. It also provides UDOT with relevant considerations to help advise and communicate with canal companies about the development of trails.

  • Crump, M., Singleton, P., Torres-Rua, A., & Pack, A. (2022). Active transportation facilities in canal corridors (UT-22.04). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/61516
  • Crump, M., Singleton, P. A., Torres-Rua, A., & Pack, A. (2022). Active transportation routes using canal corridors: Decision tools in creating successful canal trail projects. Journal of Urban Planning and Development, 148(3), 04022030. https://doi.org/10.1061/(ASCE)UP.1943-5444.0000854

Utilizing archived traffic signal performance measures for pedestrian planning & analysis – Phase II: Extending pedestrian volume estimation capabilities to unsignalized intersections

Utah Department of Transportation (UDOT), 2019–2021, PI with co-PI Keunhyun Park

Phase I research validated the use of pedestrian push-button actuations for estimating levels of walking activity at signalized intersections in Utah. This Phase II project develops methods and models predicting pedestrian volumes at unsignalized intersections, based on ATSPM data and models previously estimated in Phase I. It utilizes geospatial information about land use and built environment characteristics as well as measures of the multimodal transportation system, and develops large-scale direct-demand models for estimating intersection-level pedestrian volumes. The results can be used for traffic monitoring and forecasting, thus offering improved opportunities for pedestrian planning and operations.

  • Park, K., Singleton, P. A., Brewer, S., & Zuban, J. (2023). Pedestrians and the built environment during the COVID-19 pandemic: Changing relationships by the pandemic phases in Salt Lake County, UT, USA. Transportation Research Record: Journal of the Transportation Research Board, 2677(4), 448-462. https://doi.org/10.1177/03611981221083606
  • Singleton, P. A., Park, K., & Lee, D. H. (2021). Utilizing ATSPM data for pedestrian planning and analysis – Phase II: Extending pedestrian volume estimation capabilities to unsignalized intersections (UT-21.32). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/60875
  • Singleton, P. A., Park, K., & Lee. D. H. (2021). Varying influences of the built environment on daily and hourly pedestrian crossing volumes at signalized intersections estimated from traffic signal controller event data. Journal of Transport Geography, 93, 103067. https://doi.org/10.1016/j.jtrangeo.2021.103067

Safety in numbers? Developing improved safety predictive methods for pedestrian crashes at signalized intersections in Utah using push button-based measures of exposure

Utah Department of Transportation (UDOT), 2019–2021, PI with co-PI Michelle Mekker

One motivation for this work is to test the “safety in numbers” hypothesis for walking, which suggests that pedestrian crash rates decrease with increasing volumes of people walking. This research project also develops improved pedestrian crash prediction models at signalized intersections using pedestrian push-button measures of exposure, and it tests the safety in numbers concept. It utilizes UDOT’s ATSPM data as a measure of pedestrian exposure to develop new safety performance functions and crash modification factors. Results can improve the calibration of safety predictive methods for pedestrian–vehicle crashes at signalized intersections, and offer additional insights into the “safety in numbers” concept for walking.

  • Islam, A., Mekker, M., & Singleton, P. A. (2022). Examining pedestrian crash frequency, severity, and safety in numbers using pedestrian exposure from Utah traffic signal data. Journal of Transportation Engineering, Part A: Systems, 148(10), 04022084. https://doi.org/10.1061/JTEPBS.0000737
  • Singleton, P., Mekker, M., & Islam, A. (2021). Safety in numbers? Developing improved safety predictive methods for pedestrian crashes at signalized intersections in Utah using push button-based measures of exposure (UT-21.08). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/56362

Systemic analysis of bicycle and pedestrian safety in Utah

Utah Department of Transportation (UDOT), 2019–2021, PI

Traditional crash-based approaches to roadway safety management are reactive and ineffective for highly-dispersed bicycle and pedestrian crashes. An alternative systemic approach is more proactive, often recommending lower-cost proven countermeasures that can be applied to a larger number of sites. This research project conducts a systemic analysis of bicycle and pedestrian safety in Utah, to identify risk factors, potential treatment sites, and potential countermeasures. It compiles data on bicycle/pedestrian crashes, new and robust measures of pedestrian exposure, and roadway/community characteristics, and utilizes robust statistical methods. Results can help UDOT prioritize projects and improve safety outcomes for people walking and bicycling.

  • Singleton, P. A., Rahman, M. R., & Burbidge, S. (2022). Systemic analysis of bicycle and pedestrian safety in Utah (UT-22.07). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/62355

Utilizing archived traffic signal performance measures for pedestrian planning & analysis

Utah Department of Transportation (UDOT), 2018–2021, PI

Traditional data collection methods for pedestrian monitoring are insufficient. One potential big data source are high-resolution event logs from traffic signal controllers. Every time a pedestrian push button is pressed in Utah, this activity is recorded and archived through the Automated Traffic Signal Performance Measures (ATSPM) system. This research project explores the use of continuous pedestrian actuation data from UDOT's ATSPM system to develop estimates of pedestrian activity. It uncovers pedestrian signal typologies, validates actuations with video data collection, and develops factoring methods to convert actuations into estimates of pedestrian intersection volumes. The results can be used as exposure estimates in traffic safety analyses, health impact assessments, or for other pedestrian planning efforts.

  • Humagain, P., & Singleton, P. A. (2021). Advances in pedestrian travel monitoring: Temporal patterns and spatial characteristics using pedestrian push-button data from Utah traffic signals. Journal of Transport and Land Use, 14(1), 1341-1360. https://doi.org/10.5198/jtlu.2021.2112
  • Runa, F., & Singleton, P. A. (2021). Assessing the impacts of weather on pedestrian signal activity at 49 signalized intersections in Northern Utah. Transportation Research Record: Journal of the Transportation Research Board, 2675(6), 406-419. https://doi.org/10.1177/0361198121994111
  • Runa, F., & Singleton, P. A. (2022). Impacts of the COVID-19 pandemic on pedestrian push-button utilization and pedestrian volume model accuracy in Utah. Transportation Research Record: Journal of the Transportation Research Board. https://doi.org/10.1177/03611981221089935
  • Singleton, P. A., & Runa. F. (2021). Pedestrian traffic signal data accurately estimates pedestrian crossing volumes. Transportation Research Record: Journal of the Transportation Research Board, 2675(6), 429-440. https://doi.org/10.1177/0361198121994126
  • Singleton, P. A., Runa, F., & Humagain, P. (2020). Utilizing archived traffic signal performance measures for pedestrian planning and analysis (UT-20.17). Utah Department of Transportation. https://rosap.ntl.bts.gov/view/dot/54924
  • Singleton, P., Runa, F., & Humagain, P. (2021). singletonpa/ped-signal-data [Data set]. Zenodo. https://doi.org/10.5281/zenodo.4759089
  • Singleton, P. A., Taylor, M., Day, C., Poddar, S., Kothuri, S., & Sharma, A. (2023). Impact of COVID-19 on traffic signal systems: A survey of agency interventions and observed changes in pedestrian activity. Transportation Research Record: Journal of the Transportation Research Board, 2677(4), 192-203. https://doi.org/10.1177/03611981211026303

Needs-based approaches for representing personal transportation decision-making

Utah State University (USU), 2019–2019, PI with co-PI Antje Graul

Existing decision-making models inadequately represent emerging consumer transportation choices, especially active and sustainable transportation modes, by paying less attention to non-instrumental factors such as enjoyment, socializing, and the alignment of behavior with values. This research project first uses focus groups to evaluate the structure and contents of a proposed hierarchical “satisfaction of travel needs” decision framework. Then, it develops and validates a questionnaire measuring these concepts, thus improving an understanding of consumer behaviors and transportation policy-making.

Exploring the positive utility of travel and mode choice

National Institute for Transportation and Communities (NITC), 2016–2017, PI

Traditionally, travel is considered a disutility to be minimized, and travel demand is derived from activity demand. Recently, scholars have questioned these axioms, noting that some people may like to travel, use travel time productively, find other benefits in traveling, or travel for non-utilitarian reasons. These are instances of “the positive utility of travel” (PUT). In this project, we conceptually and empirically investigate PUT, its determinants, and its impacts on travel behavior. Using a questionnaire survey of commuters in Portland, Oregon, we collect primary data on PUT for use in a three-pronged analysis. First, we construct a measurement model of PUT and its various components. Second, we uncover traveler characteristics associated with PUT factors. Third, we tie everything together and examine the effects of PUT on commute mode choice. This study is one of the first to examine all components of PUT (travel activity and travel experience factors) at multiple levels (general, mode-specific, and trip-specific). It is also one of the first to analyze PUT’s impacts on mode choice. Our research also has important implications for transportation planning and policy, by improving knowledge of influences on (and forecasting of) sustainable modes and anticipating potential behavioral shifts with autonomous vehicles.

  • Humagain, P., De Vos, J., & Singleton, P. A. (2021). Analyzing travel captivity by measuring the gap in travel satisfaction between chosen and alternative commute modes. Transportation Research Part D: Transport and Environment, 97, 102965. https://doi.org/10.1016/j.trd.2021.102965
  • Humagain, P., & Singleton, P. A. (2020). Investigating travel time satisfaction and actual versus ideal commute times: A path analysis approach. Journal of Transport & Health, 16, 100829. https://doi.org/10.1016/j.jth.2020.100829
  • Humagain, P., & Singleton, P. A. (2020). Would you rather teleport or spend some time commuting? Investigating individuals’ teleportation preferences. Transportation Research Part F: Traffic Psychology and Behaviour, 74, 458-470. https://doi.org/10.1016/j.trf.2020.09.010
  • Humagain, P., & Singleton, P. A. (2021). Exploring satisfaction with travel time profiles towards understanding intrinsic utilities of travel time. Travel Behaviour and Society, 24, 22-33. https://doi.org/10.1016/j.tbs.2021.02.001
  • Poudel, N., & Singleton, P. A. (2022). Analyzing simple work time and commute time tradeoffs for insights into components of the value of travel time savings. Travel Behaviour and Society, 28, 330-337. https://doi.org/10.1016/j.tbs.2022.04.011
  • Runa, F., & Singleton, P. A. (2021). What factors are associated with travel liking? Evidence from commuters in Portland, Oregon. Travel Behaviour and Society, 23, 207-215. https://doi.org/10.1016/j.tbs.2021.01.004
  • Singleton, P. A. (2017). Exploring the positive utility of travel and mode choice (doctoral dissertation). Portland State University, Portland, OR. http://doi.org/10.15760/etd.3447
  • Singleton, P. A. (2017). Exploring the positive utility of travel and mode choice (NITC-DIS-1005). National Institute for Transportation and Communities. http://nitc.trec.pdx.edu/research/project/1005/
  • Singleton, P. A. (2018). How useful is travel-based multitasking? Evidence from Portland, Oregon, commuters. Transportation Research Record: Journal of the Transportation Research Board, 2672(50), 11–22. https://doi.org/10.1177/0361198118776151
  • Singleton, P. A. (2019). Multimodal travel-based multitasking during the commute: Who does what? International Journal of Sustainable Transportation, 14(2), 150–162. https://doi.org/10.1080/15568318.2018.1536237
  • Singleton, P. A. (2019). Validating the Satisfaction with Travel Scale as a measure of hedonic subjective well-being for commuting in a U.S. city. Transportation Research Part F: Psychology and Behaviour, 60, 399–414. https://doi.org/10.1016/j.trf.2018.10.029
  • Singleton, P. A. (2019). Walking (and cycling) to well-being: Modal and other determinants of subjective well-being during the commute. Travel Behaviour and Society, 16, 249–261. https://doi.org/10.1016/j.tbs.2018.02.005
  • Singleton, P. A. (2020). Exploring the Positive Utility of Travel and mode choice: Subjective well-being and travel-based multitasking during the commute. In K. G. Goulias & A. W. Davis (Eds.), Mapping the travel behavior genome (pp. 259–277). Cambridge, MA: Elsevier. https://doi.org/10.1016/B978-0-12-817340-4.00014-0
  • Singleton, P. A., & Clifton, K. J. (2021). Towards measures of affective and eudaimonic subjective well-being in the travel domain. Transportation, 48(1), 303-336. https://doi.org/10.1007/s11116-019-10055-1