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From page 22... ... 22 The steps presented in this chapter are designed to take a user of this guide from discussion and deliberation about organization goals and accessibility measures to calculating, interpreting, and communicating accessibility results (see Figure 11) Read the entire page →
From page 23... ... How to Measure and Apply Accessibility 23 The remainder of this chapter is organized around the six steps. Each step provides specific questions that users should be asking within each stage of the process and the outputs that should be produced before proceeding to the next step. Read the entire page →
From page 24... ... 24 Accessibility Measures in Practice: A Guide for Transportation Agencies federally mandated goals. (Ladders of Opportunity refers to a series of initiatives undertaken during Anthony Foxx's tenure as United States Secretary of Transportation aimed at better connecting people to opportunities and repairing the harmful legacy of transportation infrastructure projects.) Read the entire page →
From page 25... ... How to Measure and Apply Accessibility 25 or how easily the grocery store can be reached. Consider one traveler whose grocery trip takes 12 minutes total, 8 minutes of which are spent in heavy congestion. Read the entire page →
From page 26... ... 26 Accessibility Measures in Practice: A Guide for Transportation Agencies If there is no connection between an agency's or a community's objectives and the concept of accessibility, the user should reflect on whether the objectives should be revised in light of the discussion in Chapters 1 and 2. If accessibility is truly not a planning objective, the user should stop here. Read the entire page →
From page 27... ... How to Measure and Apply Accessibility 27 perspective. Rural areas may also choose to focus on different accessibility dimensions, examining access to a basket of key destinations (e.g., grocery stores, pharmacies, and libraries) Read the entire page →
From page 28... ... 28 Accessibility Measures in Practice: A Guide for Transportation Agencies particular circumstances, as determined in Step 1. For example, in this screening step, some users with limited resources might eliminate measures that require significant technical and staff resources, while others might focus on eliminating measures that are not easily applied to a specific travel mode. Read the entire page →
From page 29... ... How to Measure and Apply Accessibility 29 capacity or resources. Proximity measures require only relevant spatial data and the ability to perform basic geoprocessing. Read the entire page →
From page 30... ... 30 Accessibility Measures in Practice: A Guide for Transportation Agencies • Quality: The quality of transportation infrastructure can include pavement condition or smoothness, width, winter maintenance, lighting, safety, service frequency, reliability, and more. The extent to which these characteristics are included depends on the data used. Read the entire page →
From page 31... ... How to Measure and Apply Accessibility 31 a value of time. Access-to-opportunities, competitive, and potential-path-area measures can indicate differences in opportunities that are reachable (which have value) Read the entire page →
From page 32... ... 32 Accessibility Measures in Practice: A Guide for Transportation Agencies desirable to retain multiple measures throughout the remaining steps to determine whether and how measure definitions affect the final outcomes. 3.3.1 Accessibility Dimensions Multiple different dimensions of accessibility can be assessed, depending on the decision context and desired analytical purpose. Read the entire page →
From page 33... ... How to Measure and Apply Accessibility 33 travel, but other impedance measures can include travel distance, cost, or some combination of travel distance, time, and cost. Impedance can also reflect the quality of the network, for example by including sidewalk width, the presence of curb cuts and street lighting, transit headways, travel-time reliability, parking availability, turning restrictions, and other factors that affect the accessibility afforded by a network. Read the entire page →
From page 34... ... 34 Accessibility Measures in Practice: A Guide for Transportation Agencies of accessibility in a region, but without an understanding of the resources available to residents and the constraints they face (e.g., available modes, mandatory activity locations like place of work, ability to work remotely, income, and travel-time budgets) , place-based accessibility will only be weakly related to accessibility as experienced by people. Read the entire page →
From page 35... ... How to Measure and Apply Accessibility 35 Analysis needs might also dictate spatial scale. For example, census block-level data are only available from the decennial census. Read the entire page →
From page 36... ... 36 Accessibility Measures in Practice: A Guide for Transportation Agencies or even many circumstances. Rather, these examples provide a schematic that can be supplemented and built upon. Read the entire page →
From page 37... ... How to Measure and Apply Accessibility 37 Input data are the following: • A spatial lines layer representing bicycle infrastructure throughout the county with a variable describing type (e.g., on-street lanes, separated path, cycle track, etc.) Read the entire page →
From page 38... ... 38 Accessibility Measures in Practice: A Guide for Transportation Agencies • A table containing the total number of people and jobs located within each block group. These data typically come from in-house estimates or the U.S. Read the entire page →
From page 39... ... How to Measure and Apply Accessibility 39 2. Join jobs data to the travel-time matrix for each destination and population information to the travel-time matrix for each origin. Read the entire page →
From page 40... ... 40 Accessibility Measures in Practice: A Guide for Transportation Agencies • Any other desired demographic information that is not a part of the travel behavior data but that can be associated with individuals or spatial units in the dataset. • A matrix containing travel times by mode between every origin and destination in the study area gleaned from a travel demand model or network analysis software. Read the entire page →
From page 41... ... How to Measure and Apply Accessibility 41 4. Calculate the total number of grocery stores that can be reached in a trip chain (work-grocery store-home) Read the entire page →
From page 42... ... 42 Accessibility Measures in Practice: A Guide for Transportation Agencies 3.4.2.7 Applying Conceptual Measures Accessibility concepts can be applied without calculating precise quantitative estimates. Instead, users can employ judgment and local knowledge to assess the anticipated effects of transportation and land use changes on accessibility conditions. Read the entire page →
From page 43... ... How to Measure and Apply Accessibility 43 The example for this section illustrates one way to incorporate safety into public transit accessibility measurement, specifically assessing transit riders' perceptions of safety on the existing system. The term safety here refers not only to risk of injury and death but also to risk of verbal harassment, interactions with law enforcement, and discrimination. Read the entire page →
From page 44... ... 44 Accessibility Measures in Practice: A Guide for Transportation Agencies 3.4.3 Other Resources for Estimating Accessibility Measures Many resources are available to help users calculate accessibility measures and apply and communicate accessibility concepts. Brief descriptions for a number of these resources are included in the list that follows. Read the entire page →
From page 45... ... How to Measure and Apply Accessibility 45 to quantify. Based on theories of accessibility, the authors propose four quantifiable statements to measure generally perceived accessibility for individuals. Read the entire page →
From page 46... ... 46 Accessibility Measures in Practice: A Guide for Transportation Agencies of jobs within 30 minutes, population within ½ mile of frequent transit route, and average commute time to work by automobile) Read the entire page →
From page 47... ... How to Measure and Apply Accessibility 47 The analysts used a competitive measure to quantify job accessibility but presented the results on a standardized scale and ensured that the classification scheme was the same on maps displaying the results across their four study regions. The analysts also multiplied accessibility scores by a measure of the number of low-wage workers to identify locations where accessibility was low, but the number of workers was high. Read the entire page →
From page 48... ... Note: Overlaid dots illustrate essential worker locations. Figure 15. Read the entire page →
From page 49... ... How to Measure and Apply Accessibility 49 care to clearly label axes and minimize extraneous information like gridlines and sort bars in either ascending or descending order. Figure 17 shows how a chart can be used to communicate regional accessibility for different application areas. Read the entire page →
From page 50... ... 50 Accessibility Measures in Practice: A Guide for Transportation Agencies LEP = Limited English Proficiency Figure 17. Share of population groups with access to bikeshare stations in Boston, Massachusetts. Read the entire page →
From page 51... ... How to Measure and Apply Accessibility 51 pedestrian accessibility (see the related discussion in Section 2.3.1.2) Read the entire page →
From page 52... ... 52 Accessibility Measures in Practice: A Guide for Transportation Agencies Figure 18. Flowchart illustrating the process for considering revisions to an accessibility analysis. Read the entire page →

From page 22...

... 22 The steps presented in this chapter are designed to take a user of this guide from discussion and deliberation about organization goals and accessibility measures to calculating, interpreting, and communicating accessibility results (see Figure 11)