Skip to content

Evaluation of Bicyclist Physiological Response and Visual Attention in Commercial Vehicle Loading Zones

Download PDF  (8.04 MB)
Publication: Journal of Safety Research
Publication Date: 2023

With growing freight operations throughout the world, there is a push for transportation systems to accommodate trucks during loading and unloading operations. Currently, many urban locations do not provide loading and unloading zones, which results in trucks parking in places that obstruct bicyclist’s roadway infrastructure (e.g., bicycle lanes).

To understand the implications of these truck operations, a bicycle simulation experiment was designed to evaluate the impact of commercial vehicle loading and unloading activities on safe and efficient bicycle operations in a shared urban roadway environment. A fully counterbalanced, partially randomized, factorial design was chosen to explore three independent variables: commercial vehicle loading zone (CVLZ) sizes with three levels (i.e., no CVLZ, Min CVLZ, and Max CVLZ), courier position with three levels (i.e., no courier, behind the truck, beside the truck), and with and without loading accessories. Bicyclist’s physiological response and eye tracking were used as performance measures. Data were obtained from 48 participants, resulting in 864 observations in 18 experimental scenarios using linear mixed-effects models (LMM).

Results from the LMMs suggest that loading zone size and courier position had the greatest effect on bicyclist’s physiological responses. Bicyclists had approximately two peaks-per-minute higher when riding in the condition that included no CVLZ and courier on the side compared to the base conditions (i.e., Max CVLZ and no courier). Additionally, when the courier was beside the truck, bicyclist’s eye fixation durations (sec) were one (s) greater than when the courier was located behind the truck, indicating that bicyclists were more alert as they passed by the courier. The presence of accessories had the lowest influence on both bicyclists’ physiological response and eye tracking measures.

Practical Applications
These findings could support better roadway and CVLZ design guidelines, which will allow our urban street system to operate more efficiently, safely, and reliable for all users.

Authors: Dr. Ed McCormackDr. Anne Goodchild, Hisham Jashami, Douglas Cobb, Ivan Sinkus, Yujun Liu, David Hurwitz
Recommended Citation:
Jashami, Hisham, Douglas Cobb, Ivan Sinkus, Yujun Liu, Edward McCormack, Anne Goodchild, and David Hurwitz. “Evaluation of Bicyclist Physiological Response and Visual Attention in Commercial Vehicle Loading Zones.” Journal of Safety Research. Elsevier BV, December 2023.

Data Stories from Urban Loading Bays

Download PDF  (1.16 MB)
Publication: European Transport Research Review
Volume: 9
Publication Date: 2017

Freight vehicle parking facilities at large urban freight traffic generators, such as urban retail malls, are often characterized by a high volume of vehicle arrivals and a poor parking supply infrastructure. Recurrent congestion of freight parking facilities generates environmental (e.g. pollution), economic (e.g. delays in deliveries), and freight and social (e.g. traffic) negative externalities. Solutions aimed at either improving or better managing the existing parking infrastructure rely heavily on data and data-driven models to predict their impact and guide their implementation. In the current work, we provide a quantitative study of the parking supply and freight vehicle drivers’ parking behavior at urban retail malls.

We use as case studies two typical urban retail malls located in Singapore, and collect detailed data on freight vehicles delivering or picking up goods at these malls. Insights from this data collection effort are relayed as data stories. We first describe the parking facility at a mall as a queueing system, where freight vehicles are the agents and their decisions are the parking location choice and the parking duration.

Using the data collected, we analyze (i) the arrival rates of vehicles at the observed malls, (ii) the empirical distribution of parking durations at the loading bays, (iii) the factors that influence the parking duration, (iv) the empirical distribution of waiting times spent by freight vehicle queueing to access the loading bay, and (v) the driver parking location choices and how this choice is influenced by system congestion.

This characterization of freight driver behavior and parking facility system performance enables one to understand current challenges, and begin to explore the feasibility of freight parking and loading bay management solutions.

Authors: Dr. Giacomo Dalla Chiara, Lynette Cheah
Recommended Citation:
Dalla Chiara, G., Cheah, L. Data stories from urban loading bays. Eur. Transp. Res. Rev. 9, 50 (2017).
Technical Report

An Evaluation of Bicycle Safety Impacts of Seattle’s Commercial Vehicle Load Zones

Download PDF  (1.30 MB)
Publication Date: 2015

The Seattle Department of Transportation (SDOT) partnered with the University of Washington to explore how commercial vehicle parking in Seattle’s downtown area affects the safety of bicyclists. The hypothesis was that increased truck access to SDOT’s commercial vehicle loading zones (CVLZs) can positively contribute to bicycle safety. Because CVLZs provide truck drivers with more access to legal parking, their presence could reduce incidences of trucks parking illegally in the street or blocking bicycle lanes, thus reducing the necessity for bicyclists to maneuver around them. This research explored this hypothesis by using four methods, an analysis of bike-trucks accident data, interviews with bicyclists and truck drivers who frequently travel in downtown Seattle, analysis of video recordings of cyclists riding downtown, and observations of truck loading/unloading operations downtown.

The research determined that from bicyclists’ perspectives, illegally parked trucks were a more serious problem than the locations of CVLZs. Therefore, increasing the availability of legal truck parking should have a positive effect on bicyclist safety and level of stress. When trucks park in the bike lane, cyclists are required to maneuver into the stream of traffic, increasing level of exposure and accident risk. Similarly, both the cyclist interviews and video data indicated that construction sites are problematic locations for illegally parked trucks blocking cyclist travel lanes. Better enforcement of parking regulations near construction sites and better site planning would help alleviate a significant amount of conflict between cyclists and parked trucks.

Loading zones on higher speed or busy streets or in areas where cyclists travel downhill increase the danger of those areas. In some areas, it may be possible to relocate loading zones around the corner, onto less busy side streets, to eliminate the need for cyclists to choose between merging into a busy lane to pass a truck or passing close enough to the truck that the delivery operations may put obstacles in the bicyclist’s path. If loading zones are moved, the zones should be situated at the beginning of the block and should allow drivers to still reach the businesses they are serving quickly and without having to maneuver or cross a street. This will encourage the use of the loading zone as opposed to illegal parking.

Recommended Citation:
Butrina, Polina, Edward McCormack, Anne Goodchild, and Jerome Drescher. "An Evaluation of Bicycle Safety Impacts of Seattle’s Commercial Vehicle Load Zones." (2016).
Technical Report

Safe Truck Parking in PacTrans Interstate Corridors: I-5 and I-90

Download PDF  (1.46 MB)
Publication Date: 2018

Unresolved safety issues caused by truck parking shortages in high-demand locations are of keen importance to the State Departments of Transportation (DOTs) participating in the Regional PacTrans Center and to the thousands of trucking companies and drivers using the Interstate 5 (I-5) and Interstate 90 (I-90) corridors. Safety issues include serious and/or fatal crashes that may be related to the lack of safe and secure parking, and illegal/unofficial parking on entrance and exit ramps, shoulders, and freeway lanes that create hazards for motorists during severe weather.

WSDOT completed a statewide truck parking study in December 2016, and the Oregon Department of Transportation (ODOT) published a report on truck parking along the US97 corridor in July 2017. Both states are interested in addressing safety issues inherent in the current lack of truck parking capacity. Researchers at the Supply Chain Transportation and Logistics Center (SCTL) at the University of Washington developed this project’s research goals with WSDOT to support their work.


The project goals are to:
  • Provide data-based decision support to WSDOT and neighboring states as they develop solutions for the lack of safe truck parking along the I-5 and I-90 corridors.
  • Develop new and valuable insights from truck drivers’ expertise on safety problems resulting from the lack of truck parking capacity on these corridors.
To achieve these goals, the research team first conducted a research scan of existing studies and other online reports that describe the lack of parking in high-demand locations along the I-5 and I-90 corridors in the PacTrans region.

Future Trends 

SCTL identified three trends in the truck parking industry that will affect the truck parking shortage in the future:
  1. The rising cost of land in growing metropolitan areas will continue to intensify this problem. Rapidly increasing land costs create pressure on truck service firms to either create new revenue streams (charging for parking that was formerly included for ‘free’ along with retail fuel sales) or relocate further from metro centers if they cannot compete with higher-value land uses near highway interchanges. Also, manufacturing and wholesale facilities that generate a high number of truck trips will likely continue to maximize building footprints on parcels, reducing available land for on-site truck parking.
  2. Federal regulatory changes are likely to increase long-haul truck parking demand in the next 10 years. In the short term, the electronic logging device (ELD) mandate beginning in 2018 will change driver behavior. Although some long-haul drivers have not strictly followed federal Hours of Service (HOS) regulations in the past, under the new ELD mandate they are more likely to stop and park for required rest periods because it will be more difficult to evade detection. In the next 10 years, additional federal regulations may be enacted and shorten drivers’ HOS again, thereby increasing demand for more rest stops on the Interstate Highway System and other major truck routes.
  3. In the longer term, emerging autonomous and cooperative truck technologies that address driver fatigue are likely to reduce demand for truck stops in rural areas – but not near cities. The truck driver interviews conducted for this project show that drivers stop for business reasons, not just for safety rest periods.

Finally, SCTL conducted 184 interviews of truck drivers over a three-week time period at two high-demand truck stops on the I-5 and I-90 corridors to determine: (a) origin and destination of trips; (b) connection to the Ports of Seattle and Tacoma; (c) drivers’ perceptions of safety issues caused by a lack of truck parking; (d) types of commodities carried; and (e) why drivers parked at these rest stops.

Key Findings 

The SCTL Center’s research provides new data and insights to answer questions under discussion between state, local, and regional transportation agencies and communities in the central Puget Sound region. The research results supported development of the Washington State Freight Mobility Plan. However the project’s findings have not resulted in public funding for additional parking in high-demand locations near I5 and I-90.

One of the most topical questions is whether the state’s economy and/or the Ports of Seattle and Tacoma benefit from the truck trips that require rest stops near the Seattle-Tacoma Bellevue metropolitan area. This question is central to understanding their proportional roles and funding responsibilities to add parking capacity where it is scarce: in the central Puget Sound region.

  • The on-site truck driver survey showed that there is an extremely strong tie between truck parking activity and the state’s economy: 91% percent of trucks parked along I-90 (at TA Seattle East Travel Center in North Bend) and 87% of those parked along I-5 (at the Mustard Seed in Sumner) delivered goods to businesses and other customers within Washington State. The evidence belies the hypothesis that most trucks using parking facilities in Washington are passing through the state and therefore provide no economic value to it.
  • Most drivers using the two truck parking facilities in central Puget Sound were not going to either the Port of Seattle or Port of Tacoma. In fact, 83% of truck drivers parked near I-90 and 78% near I-5 did not go to either of the two container ports. Although port-related traffic uses iv the truck parking facilities, it is not the major cause of increased parking demand at these locations.
  • Why do truck drivers park in these facilities? Surprisingly, more park there – and park longer – for business reasons rather than for safety reasons. The largest group of drivers (34% of those interviewed at TA Seattle East and 36% at Mustard Seed) said their primary reason for the stop was to wait to meet a specific delivery time at their destination or wait to locate another load. When SCTL compared the number of hours parked with the primary reason for parking, it found that delivery operations were the largest driver for longer stays.

The research findings have been used to communicate the importance of providing truck parking in high-demand areas in Washington State, particularly near I-5 south of Seattle and along I-90 near North Bend, to local officials, WSDOT, and other state officials.

By an overwhelming margin, truck drivers who parked along I-5 and I90 near the Seattle-Tacoma-Bellevue metropolitan area delivered goods in Washington State, providing strong evidence that their activities support the state’s economy and residents.

Recommended Citation:
Giron-Valderrama, Gabriela, Barbara Ivanov, and Anne Goodchild. "Safe Truck Parking in PacTrans Interstate Corridors: I-5 and I-90." (2018).

Are Cities’ Delivery Spaces in the Right Places? Mapping Truck Load/Unload Locations

Download PDF  (5.67 MB)
Publication: City Logistics 2: Modeling and Planning Initiatives (Proceedings of the 2017 International Conference on City Logistics)
Volume: 2
Pages: 351-368
Publication Date: 2018

Two converging trends – the rise of e‐commerce and urban population growth – challenge cities facing competing uses for road, curb and alley space. The University of Washington has formed a living Urban Freight Lab to solve city logistics problems that cross private and public sector boundaries. To assess the capacity of the city’s truck load/unload spaces, the lab collected GIS coordinates for private truck loading bays, and combined them with public GIS layers to create a comprehensive map of the city’s truck parking infrastructure. The chapter offers a practical approach to identify useful existent urban GIS data for little or no cost; collect original granular urban truck data for private freight bays and loading docks; and overlay the existing GIS layers and a new layer to study city‐wide truck parking capacity. The Urban Freight Lab’s first research project is addressing the “Final 50 Feet” of the urban delivery system.

Recommended Citation:
Goodchild, Anne, Barb Ivanov, Ed McCormack, Anne Moudon, Jason Scully, José Machado Leon, and Gabriela Giron Valderrama. Are Cities' Delivery Spaces in the Right Places? Mapping Truck Load/Unload Locations: Modeling and Planning Initiatives. City Logistics 2: Modeling and Planning Initiatives (2018): 351-368. 10.1002/9781119425526.ch21