Accessibility Evaluation of the Metro Transit A-Line

Recently Published:
Change in number of jobs accessible within 30 minutes by transit available with Metro Transit A-Line
Change in number of jobs accessible within 30 minutes by transit available with Metro Transit A-Line
Abstract: This report evaluates the Accessibility of the Metro Transit A-Line arterial bus rapid transit system serving St. Paul and Minneapolis, Minnesota. It is found that overall the A-Line increases accessibility compared to the previous service provided by the local bus, though some areas lose accessibility if they are not near a new A-Line stop.
Keywords: Accessibility, Bus Rapid Transit, Public Transport, Evaluation
Persistent link to this item http://hdl.handle.net/11299/180900
Funding information
United States Department of Transportation, Federal Highway Administration
Suggested Citation
Palmateer, Chelsey; Owen, Andrew; Levinson, David M. (2016). Accessibility Evaluation of the Metro Transit A-Line.Accessibility Observatory, University of Minnesota. Retrieved from the University of Minnesota Digital Conservancy, http://hdl.handle.net/11299/180900.

Improving Urban Access: New Approaches to Funding Transport Investment

A new book is out, I had the opportunity to preview and blurb it:

Improving Urban Access: New Approaches to Funding Transport Investment

Edited by Elliott D. SclarMåns LönnrothChristian Wolmar. 2016 – Routledge

 

Reviews

“Improving Urban Access” provides a wide-ranging introduction to the issues of funding and financing urban transport, ranging from how we got into the current predicament to the prospects for a variety of solutions that might make transport more inclusive, efficiently funded, and soundly managed. The ideas discussed here should be deeply understood by everyone concerned with transport policy and planning.” – David M. Levinson, Professor, Department of Civil Engineering, Richard P. Braun/CTS Chair in Transportation Engineering

Improving Urban Access is a must-read for the 21st century generation of transport and urban planners. Lessons learned have called for a bold rethinking of planning and implementation of a highway-centered landscape. With an emphasis on access – where access addresses quality of life and place, old models of mobility give way to rethinking the institutions that serve our growing urban areas, the ways in which citizens can finance new transport modes and how – we can achieve a more equitable social structure.” – Robert E. Paaswell, Distinguished Professor City University, City College of New York, former CEO of the Chicago Transit Authority

“Many public servants are so desperate to “find” additional revenues for urban transportation that they may lose sight of what they are trying to accomplish and why. This book does an excellent job of reminding us that how something is funded directly impacts the societal outcomes we are wishing to achieve, pointing out that careful consideration of funding mechanisms is absolutely critical to success.” – Joshua Schank, Chief Innovation Officer, Los Angeles County Metro, former President of the Eno Center for Transportation

“Transportation policy scholarship is changing slowly but dramatically, and this second stimulating milestone book by these editors charts that transition. Contributors forcefully address the most important unresolved questions as transportation thinking moves from forecasting demand and providing facilities to a new emphasis on access, social and economic equity, and environmental sustainability.” – Martin Wachs, Distinguished Professor Emeritus, Urban Planning and Civil Engineering University of California Los Angles and University of California, Berkeley

Temporal Sampling Intervals and Service Frequency Harmonics in Transit Accessibility Evaluation

Recent working paper by my Accessibility Observatory colleagues:

Box plots for sampling strategy performance over all blocks at each sampling frquency. Boxes show inter-quartile range (25th – 50th percentile) with horizontal medial line; whiskers extend 1.5×IQR above and below. Outliers are plotted individually. Mean is indicated by a dot.
Box plots for sampling strategy performance over all blocks at each sampling frquency. Boxes show inter-quartile range (25th – 50th percentile) with horizontal medial line; whiskers extend 1.5×IQR above and below. Outliers are plotted individually. Mean is indicated by a dot.

Abstract

In the context of public transit networks, repeated calculation of accessibility at multiple departure times provides a more robust representation of local accessibility. However, these calculations can require significant amounts of time and/or computing power. One way to reduce these requirements is to calculate accessibility only for a sample of time points over a time window of interest, rather than every one. To date, many accessibility evaluation project have employed temporal sampling strategies, but the effects of different strategies have not been investigated and their performance has not been compared. Using detailed block-level accessibility calculated at 1-minute intervals as a reference dataset, four different temporal sampling strategies are evaluated. Systematic sampling at a regular interval performs well on average but is susceptible to spatially-clustered harmonic error effects which may bias aggregate accessibility results. A constrained random walk sampling strategy provides slightly worse average sample error, but eliminates the risk of harmonic error effects.

Accessibility Analysis of Risk Severity

Recent working paper

Risk severity: Links by 30 minute accessibility loss should they be removed from the network
Risk severity: Links by 30 minute accessibility loss should they be removed from the network

Risk severity in transportation network analysis is defined as the effects of a  link or network failure on the whole system. Change accessibility (reduction in the number of jobs which can be reached) is used as an integrated indicator to reflect the severity of a link outage.  The changes of accessibility before-and-after the removing of a freeway segment from the network represent its risk severity. The  analysis in the Minneapolis – St. Paul (Twin Cities) region  show that links near  downtown Minneapolis have relative higher risk severity than those in  rural area. The geographical distribution of links with the highest risk severity displays the property that these links tend to be near or at the intersection of freeways. Risk severity of these links based on the accessibility to jobs and to workers at different time thresholds and during different dayparts are also analyzed in the paper. The research finds that network structure measures: betweenness, straightness and closeness, help explain the severity of loss due to network outage.

Keywords: GPS data, congestion, network structure, accessibility

Evaluating the “Safety In Numbers” Effect With Estimated Pedestrian Activity

Recent working paper:

Pedestrian risk vs. PM pedestrian flow
Pedestrian risk vs. PM pedestrian flow

 

Pedestrian and bicyclist collision risk assessment offers a powerful and informative tool in urban planning applications, and can greatly serve to inform proper placement of improvements and treatment projects. However, sufficiently detailed data regarding pedestrian and bicycle activity are not readily available for many urban areas, and thus the activity levels and collision risk levels must be estimated. This study builds upon other current work by Murphy et al. (1) regarding pedestrian and bicycle activity estimation based on centrality and accessibility metrics, and extends the analysis techniques to estimation of pedestrian collision risk. The Safety In Numbers phenomenon, which refers to the observable effect that pedestrians become safer when there are more pedestrians present in a given area, i.e. that the individual per-pedestrian risk of a collision decreases with additional pedestrians, is a readily observed phenomenon that has been studied previously. The effect is investigated and observed in acquired traffic data, as well as estimated data, in Minneapolis, Minnesota.

Accessibility and Centrality Based Estimation of Urban Pedestrian Activity

Recent working paper

Estimated evening peak period pedestrian activity
Estimated evening peak period pedestrian activity

Non-motorized transportation, particularly including walking and bicycling, are increasingly becoming important modes in modern cities, for reasons including individual and societal wellness, avoiding negative environmental impacts of other modes, and resource availability. Institutions governing development and management of urban areas are increasingly keen to include walking and bicycling in urban planning and engineering; however, proper placement of improvements and treatments depends on the availability of good usage data. This study attempts to predict pedestrian activity at 1123 intersections in the Midwestern, US city of Minneapolis, Minnesota, using scalable and transferable predictive variables such as economic accessibility by sector, betweenness network centrality, and automobile traffic levels. Accessibility to jobs by walking and transit, automobile traffic, and accessibility to certain economic job categories (Education, Finance) were found to be significant predictors of increased pedestrian traffic, while accessibility to other economic job categories (Management, Utilities) were found to be significant predictors of decreased pedestrian traffic. Betweenness centrality was not found to be a significant predictor of pedestrian traffic, however the specific calculation methodology can be further tailored to reflect real-world pedestrian use-cases in urban areas. Accessibility-based analysis may provide city planners and engineers with an additional tool to predict pedestrian and bicycle traffic where counts may be difficult to obtain, or otherwise unavailable.

Accessibility and Transit Performance

Recent working paper

Residual plot of the parsimonious regression model
Residual plot of the parsimonious regression model

This study disentangles the impact of financial and physical dimensions of transit service operators on net transit accessibility for 46 of the 50 largest metropolitan areas in the United States. To investigate this interaction along with the production efficiency of transit agencies, two types of analysis are used: a set of linear and quadratic regressions and a data envelopment analysis. We find that vehicle revenue kilometers and operational expenses play a pivotal role in enhancing the accessibility to jobs by transit. The bivariate linear regression models indicate a 1% increase in operational expenses and vehicle revenue kilometers increase the number of jobs that can be reached within 30 minutes by 0.96 and 0.95%, respectively. The results of the quadratic functional form, also, show transit services may have both increasing and decreasing accessibility returns to scale depending on system size, and the results are sensitive to the model used. Overall, the highest system efficiency (access produced per input) is found in the New York, Washington, and Milwaukee metropolitan areas, while Riverside, Detroit, and Austin perform with the lowest efficiency.

Keywords: Public transit; Accessibility; Envelope of output; Returns to scale; Metropolitan area

“Transit Makes you Short”: On Health Impact Assessment of Transportation and the Built Environment

Recent working paper

Coefficient-p-value-sample-size (CPS) chart for Transit Share variable
Coefficient-p-value-sample-size (CPS) chart for Transit Share variable

The current research provides a test framework to understand whether and to what extent increasing public transit use and accessibility by transit affect health. To this end, the effect of transit mode share and accessibility by transit on general health, body mass index, and height are investigated, while controlling for socioeconomic, demographic, and physical activity factors. The coefficient-p-value-sample-size chart is created and effect size analysis are conducted to explore whether the transit use is practically significant. Building on the results of the analysis, we found that the transit mode share and accessibility by transit are not practically significant, and the power of large-sample misrepresents the effect of transit on public health. The results, also, highlight the importance of data and variable selection by portraying a significant correlation between transit use and height in a multivariate regression analysis. What becomes clear from this study is that in spite of the mushrooming interdisciplinary studies in the nexus of transportation and health arena, researchers often propose short- and long-term policies blindly, while failing to report the inherent explanatory power of variables. We show that there is a thin line between false positive and true negative results. From the weakness of p-values perspective, further, we strove to alert both researchers and practitioners to the dangerous pitfall deriving from the power of large- samples. Building the results on just significance and sign of the parameter of interest is worthless, unless the magnitude of effect size is carefully quantified post analysis.

Keywords: Public transit; BRFSS data; ACS data; Accessibility to jobs; p-hacking