Abstract
Reduction in urban motorist lanes has grown in popularity in recent years in an effort to reduce collisions and accommodate increased desire for active transportation. While these projects have been innovative and popular, there isn't yet a strong consensus on whether these projects deliver on their promised benefits, with a common problem being a lack of sufficient before and after data collection to show the effects.
We focus on the upcoming Forbes Avenue reconstruction project that will occur along the north edge of campus (yet with the completion of the new Tepper quad in several years will cut through the center of an emerging campus footprint). This project is a prototype of a 'smart mobility' implementation, involving new technology, multiple modes and measures to improve bike, pedestrian and vehicle safety, and will be funded by the Pennsylvania Department of Transportation, Southwestern Pennsylvania Commission, and CMU.
We propose a multi-criteria 'before and after' impact assessment. Major aspects to be assessed include:
* Changes to vehicular volumes, speeds, travel times and emissions
* Changes in public transit routing, frequency, and ridership.
* Changes in use or demand for on-campus and near-campus parking.
* Changes to bike and pedestrian use of Forbes Avenue.
* Perceptions of safety, accessibility and aesthetics for Forbes Avenue.
* Changes in local traffic noise
We have already archived significant amounts of 'before' data on Forbes Avenue and will be gathering more by deploying a network of various air, audio, video, and related sensors along Forbes Ave.
SPC is interested in this assessment as a means of calibrating their project selection criteria. We believe the City of Pittsburgh and PennDOT are also interested in a comprehensive assessment. We expect to end with several professional papers and a policy maker's guide describing this smart mobility project's impacts and provides a basis for other such projects.
Description
A reduction in urban motorist lanes, most commonly from four to three with a center turn lane and bicycle lane additions, has grown in popularity in recent years in an effort to reduce collisions and accommodate increased desire for active transportation. General trends extracted from 24 case studies show a reduction in accidents, increased pedestrian/cyclist counts, similar traffic counts, and a small increase in travel time for similar roadway narrowing projects [1]. Results show large variation depending on location and existing transportation infrastructure. In another study based on six comprehensive assessments, total crashes reduced by 19% and 47% in urban and rural areas respectively [2]. A study conducted along Ocean Park Boulevard in Santa Monica, CA resulted in unchanged traffic counts, however, vehicle type distribution shifted to a larger proportion of new light duty vehicles, which reduced on-roadway ultra-fine particulates [3]. Several other reports observed increased pedestrian and cyclist traffic after road conversion, however, it is difficult to determine if increased counts are due to recreational activity or mode shift [3,4,5]. Road narrowing projects also reduce traffic speeds resulting in decreased noise levels. In addition, appropriate signal timing can alleviate additional road noise by controlling traffic flow and minimizing stop and go effects [6].
When road diets sections observed ADTs greater than 20,000, it is estimated that neighboring streets will observe increased traffic volumes because congestion on the road diet section increases to a point where traffic begins to divert to alternate routes [7]. The evaluation of the Valencia Street roadway diet in San Francisco produced a traffic volume decrease of 10% along Valencia while the four nearby parallel streets all observed increases in traffic volume ranging from 2-8%. The total ADT for the five streets increased by 1%, meaning that traffic, at least in the short term, chose alternative routes rather than shifting transportation mode [4]. However, a different study along Telegraph Avenue in Oakland, CA observed mode share of pedestrians and cyclists increase from 8% to 16% and the mode share of pedestrians, cyclists, and public transit users increase from 26% to 28% along Telegraph Ave during peak demand. A bicycle intercept survey was conducted to understand greater network impacts, and 8% of the riders surveyed shifted travel modes after Telegraph Avenue reconstruction was complete [8]. The remaining additional riders along Telegraph changed routes to utilize the protected bike lanes.
Conversion of motorist-centric 4-lane urban roadways to 3-lane designs focused on user choice results in a wide variety of community benefits. However, negative impacts such as increased congestion and travel time can occur when traffic volumes are high. Since project location, existing infrastructure and public transit options affect project outcomes in diverse ways, local analysis is required to accurately quantify benefits and provide insight for future decision making
Since 2012, and consistent with the CMU Institutional Master Plan, several planning studies have been conducted to support the reconfiguration of the Forbes Avenue arterial and corridor. These studies have examined different geographic areas, with the most extensive including Forbes and Fifth Avenues from Margaret Morrison to the Birmingham Bridge. These studies are significant because the Forbes and Fifth corridor in Oakland support about 100,000 residents, workers, and students per day. In 2018, a major reconfiguration will be implemented in the heart of CMU's campus along Forbes Ave between Margaret Morrison and Craig Street. Key features designed (by the CMU Campus Design and Facilities Development organization and GAI Consultants in collaborative funding with SPC and PA DOT) that will be built as part of the reconfiguration will be:
* Reduction of vehicle lanes from four to three with the center lane dedicated to turning movements.
* Introduction of bike lanes.
* Reconfiguration and relocation of several intersections (including several pedestrian-only crossings) and adoption of advanced traffic signals.
* Construction of bus turn outs, new street lights, new pavement and new street furniture.
Thus, this project is a prototype of a 'smart mobility' implementation, involving new technology, multiple modes and measures to improve bike, pedestrian and vehicle safety. We propose a multi-criteria 'before and after' impact assessment for this reconfiguration project. Major aspects to be assessed include:
* Changes to vehicular volumes, speeds, travel times and vehicle emissions on Forbes Avenue and surrounding streets.
* Changes in public transit routing, frequency, and ridership.
* Changes in use or demand for on-campus and near-campus parking.
* Changes to bike and pedestrian use of Forbes Avenue.
* Air quality changes.
* Perceptions of safety, accessibility and aesthetics for Forbes Avenue.
* Changes in local traffic noise
SPC is interested in an impact assessment as a means of calibrating their project selection criteria. We believe the City of Pittsburgh and PADOT are also interested in a comprehensive assessment. We expect to end with several professional papers and a policy maker's guide that tells the story of this smart mobility project's impacts and provides a basis for other such projects.
Primary tasks in the study will be to assemble comprehensive mobility data for before (2016 to 2017), during construction (2018) and after (2018-2019) periods. As we have already gathered significant amounts of 'before' data on Forbes Avenue by working with CMU and GAI for data used in their project designs, and the construction will begin this summer, we believe the timing of this project is ideal although the after period will extend slightly beyond the Mobility21 project funding year (we do not expect that to be an issue). We have also been participating in monthly meetings with the CMU CDFD project manager (Bob Reppe) and GAI Consultants since early fall 2017.
The research effort on this project will be accomplished largely through support of a Civil and Environmental Engineering PhD student (Rick Grahn) and supervised by faculty members identified.
Timeline
Given the before-during-after nature of our intended study, we separate milestones along those time periods, as described below.
Before: From initial discussions we have already been archiving potentially useful data for the criteria of interest in this study, and will continue to seek additional 'before project' data sources through September 2018.
During: We will be preparing to gather new data over the next 8 months, by siting locations for audio, video, and other devices along the Forbes corridor, and will collaborate with the CMU Center for Atmospheric Particle Studies (CAPS) to leverage emissions and air quality data from sensors that they maintain along the corridor. These will be used to study both the during construction and 'after' periods. [We have budgeted a small amount for these devices (and will self-install).] We will also begin to develop relevant data models and structures to efficiently do the before and after modeling as the construction period ends.
After: Beginning in early 2019, we will begin to perform the before vs. after comparisons for the criteria of interest listed above, in collaboration with SPC (and the City and PennDOT if they remain interested).
Strategic Description / RD&T
Deployment Plan
The 'deployment plan' for this project is not like that of a typical DOT center project which may develop technology and then seek to put it into the field. Instead, as noted above, our deployment is only as part of the testbed used to collect data for the before-during-after analysis.
That said, we will deliver our results to SPC since, as noted above, they are interested in how the benefits of this project as we have quantified aligned to their project selection criteria used for projects.
Expected Outcomes/Impacts
We anticipate preparing several professional papers, presentations for local, state and national entities, and an accessible policy guide to smart mobility implementations. We will also make all data and methods used available to other researchers by web dissemination (including by use of open source frameworks, if relevant).
Expected Outputs
TRID
Individuals Involved
| Email |
Name |
Affiliation |
Role |
Position |
| rgrahn@andrew.cmu.edu |
Grahn, Rick |
Carnegie Mellon University |
Other |
Student - PhD |
| cth@cmu.edu |
Hendrickson, Chris |
CIT/Heinz |
Co-PI |
Faculty - Tenured |
| hsm@cmu.edu |
Matthews, H. Scott |
Carnegie Mellon University |
PI |
Faculty - Tenured |
| seanqian@cmu.edu |
Qian, Sean |
Carnegie Mellon University |
Co-PI |
Faculty - Untenured, Tenure Track |
Budget
Amount of UTC Funds Awarded
$90000.00
Total Project Budget (from all funding sources)
$168000.00
Documents
| Type |
Name |
Uploaded |
| Data Management Plan |
Data_management_Plan_for_Mobility21_Forbes.docx |
Jan. 13, 2018, 1:17 p.m. |
| Progress Report |
181_Progress_Report_2018-09-30 |
Sept. 30, 2018, 6:25 a.m. |
| Progress Report |
181_Progress_Report_2019-03-30 |
May 4, 2019, 5:57 a.m. |
| Presentation |
Mobility21_Meeting_Update_Nov_2019.pptx |
April 6, 2020, 8:10 p.m. |
| Progress Report |
181_Progress_Report_2020-03-30 |
April 6, 2020, 8:37 p.m. |
| Final Report |
181-Forbes_Final_Report_VLWIN7x.pdf |
Dec. 15, 2020, 4:56 a.m. |
| Publication |
Societal Impacts of a Complete Street Project in a Mixed Urban Corridor: Case Study in Pittsburgh, 2021, Journal of Infrastructure Systems. |
March 1, 2021, 5:33 a.m. |
Match Sources
No match sources!
Partners
| Name |
Type |
| CDFD |
Deployment Partner Deployment Partner |
| GAI Consultants |
Deployment Partner Deployment Partner |
| Southwestern Pennsylvania Commission |
Deployment Partner Deployment Partner |
