Skip to content
Urban Freight Lab

Research Topic: Surface Transportation

Surface transport is the movement of people or goods across the surface, including road, rail, water, and pipeline, and excluding air.

Dynamically Managed Curb Space Pilot

Transportation Network Company (TNC) usage in Seattle has been increasing every quarter since 2015 when the City of Seattle Department of Transportation (SDOT) began collecting data. TNC trips exceeded 20 million in 2017, a 46% increase from total reported trips in 2016. This has led to concerns about congestion and pedestrian safety as cars and people take risks to connect at the curb and in the right-of-way. By providing additional curb capacity through increased passenger loading zones and directing customers via in-app messaging, the City may be able to reduce congestion and unsafe vehicle/people movements during peak traffic and late-night hours.

Other cities have attempted to study the impacts of increased usage of passenger loading zones (e.g., San Francisco, Washington D.C.), with varying success, but no standard methodology exists for cities to assess the potential for reallocated curb space and the subsequent impacts of those changes. SDOT is taking a data-driven approach to curb reallocation and traffic network impacts, modeling the work SDOT has done to quantify demand in paid parking areas and set rates accordingly. The main goals of this pilot are three-fold: increase pedestrian safety, minimize congestion impacts on the larger transportation network, and build a scalable methodology for assessment and implementation of curb allocation to accommodate this new mobility service.

The Supply Chain Transportation & Logistics Center and SDOT will work in collaboration with employers, transit operators, and TNCs to test a variety of strategies to mitigate the traffic impacts of TNC pick-ups on the greater transportation network and improve safety for passengers and drivers. Strategies include increasing the number of passenger loading zones in high-traffic pick-up areas and geofenced pick-up or black-out areas. Curb and street use data will be collected under each alternative and compared to baseline data.

Presentation

Investigation of Private Loading Bay Operations in Seattle’s Central Business District

 
Download Slides PDF  (0.47 MB)
URL: https://metrans.org/inuf_2022-papers_presentations
Publication: 9th International Urban Freight Conference, Long Beach, May 2022
Publication Date: 2022
Summary:

Cities need new load/unload space concepts to efficiently move freight, particularly as autonomous vehicles (both passenger and freight) become feasible. This research aims to: understand the importance of off-street commercial parking, understand how off-street facilities are managed, and determine whether off-street commercial parking is an underutilized resource for urban goods delivery.

Researchers determined the locations of commercial and residential buildings in Seattle’s Central Business District with off-street delivery infrastructure, established communication with property management or building operators, and conducted interviews regarding facility management, usage, roadblocks in design/operations, and utilization.

This research finds that overbooking of off-street space is infrequent, most facility management is done by simple tenant booking systems, buildings relying primarily on curb space notes that infrastructure and operations were hindered by municipal services — especially when connecting to alleyways.

Authors: Griffin DonnellyDr. Anne Goodchild
Recommended Citation:
Griffin Donnelly and Anne Goodchild. Investigation of Private Loading Bay Operations in Seattle's Central Business District. 9th International Urban Freight Conference (INUF), Long Beach, CA May 2022.
Technical Report

Characterization of Seattle’s Commercial Traffic Patterns: A Greater Downtown Area and Ballard/Interbay Vehicle Count and Evaluation

 
Download PDF  (5.59 MB)
Publication Date: 2021
Summary:

Seattle now ranks as the nation’s sixth-fastest growing city and is among the nation’s densest. As the city grows, so do truck volumes — volumes tied to economic growth for Seattle and the region as a whole. But many streets are already at capacity during peak hours and bottleneck conditions are worsening. This project is designed to deliver critical granular baseline data on commercial vehicle movement in two key areas of the city to help the city effectively and efficiently plan for growing freight demand.

This timely research from the Urban Freight Lab (UFL) on behalf of the Seattle Department of Transportation produces Seattle’s first complete estimate of Greater Downtown area traffic volumes. And it offers a detailed analysis of commercial vehicle traffic in and around one of the city’s two major industrial centers, the Ballard-Interbay Northern Manufacturing Industrial Center.

These efforts are significant because the city has lacked a comprehensive estimate of commercial vehicle volumes until now. In the Greater Downtown area, the cordon counts (tracking traffic in and out of 39 entry/exit points) alongside traffic volume estimates will provide a powerful tool for local government to model, evaluate, develop, and refine transportation planning policies. This study lays the groundwork for the first commercial vehicle traffic model that will enable the evaluation of different freight planning and traffic management strategies, economic growth scenarios, and application of new freight vehicle technologies. Ballard-Interbay is slated for major infrastructure projects in the coming years, including new Sound Transit stations and critical bridge replacements. This analysis will help inform these projects, which are critical to an efficient, reliable transportation system for goods and people.

One overall finding merits attention as it suggests the need to update some of the freight network element categories defined in the current Seattle Freight Master Plan. The SCTL research team finds that the volume of smaller commercial vehicles (such as pick-ups, vans, and step vans) is significant in both the Greater Downtown area and Ballard-Interbay, representing more than half of all commercial vehicles observed (54% in the Greater Downtown area and 60% in Ballard-Interbay.) Among those smaller commercial vehicles, it is service vehicles that constitute a significant share of commercial traffic (representing 30% in the Greater Downtown area and 40% in Ballard-Interbay.) Among the myriad possible ramifications of this finding is parking planning. An earlier SCTL research paper (1) found service vehicles tend to have longer dwell times, with 44% of all observed service vehicles parked for more than 30 minutes and 27% parked for an hour or more. Given this study’s finding of service vehicles representing a significant share of commercial traffic volume, these vehicles may have a disproportionate impact on parking space rates at the curb.

Comprehensive planning requires comprehensive data. Yet cities like Seattle often lack the detailed data needed for effective freight planning, from peak hours and fleet composition to activity type and gateways of entry/exit. And if cities do have data, they are often too highly aggregated to be useful for management or planning or suffer from lack of comparability or data confidentiality problems.

Currently, urban traffic volume estimates by Puget Sound agencies are limited in spatial and vehicular detail. For example:

  • Seattle Department of Transportation (SDOT) is responsible for recording traffic counts through the year on selected arterial streets in Seattle, providing a seasonally adjusted average weekday total vehicle traffic for all lanes at all count locations.
  • Washington Department of Transportation (WSDOT) provides annual average daily traffic volumes in select locations of their jurisdiction, including the major interstates and state highways in the Seattle area. This data includes truck volume separated into three types: single, double, and triple units.
  • Puget Sound Regional Council (PSRC) regional truck model has three levels of vehicle classification: light commercial, medium trucks, and heavy trucks. This is based on WSDOT Annual Traffic Flow’s count locations and additional manual counts for model validation through the Puget Sound Region.

But none of these existing efforts produce enough detail to understand Seattle’s vehicle movements or connect them with economic activity. To fill the gap, Seattle could consider adopting a standard freight-data reporting system that would emphasize collecting and distributing richer and better data for time-series analysis and other freight forecasting, similar to systems used in cities like Toronto and London. Seattle is a national leader when it comes to freight master plans. This study offers a critical snapshot of the detailed data needed for effective policy and planning, potentially informing everything from road maintenance and traffic signals to electric vehicle charging station sites and possible proposals for congestion pricing. That said, Seattle could benefit greatly from sustained, ongoing detailed data reporting.

Authors: Gabriela Girón-ValderramaDr. Anne Goodchild
Recommended Citation:
Urban Freight Lab (2021). Characterization of Seattle's Commercial Traffic Patterns: A Greater Downtown Area and Ballard/Interbay Vehicle Count and Evaluation.