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This data provides a high-level measure of the Route Directness Index (RDI) associated with potential roadway crossing activities in population centers. The data has been developed for generalized locations along Washington State highways. This RDI data provides planners and designers with a general, but objective measure of out of direction travel requirements for a reference trip. The data is best suited for analysis of pedestrian and bicyclist trip making at regional or statewide scales. This layer uses available network input data and does not capture all potential crossing locations or evaluate the suitability of a given crossing for active travel. |
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This data provides a high-level measure of the Route Directness Index (RDI) associated with potential roadway crossing activities in population centers. The data has been developed for generalized locations along Washington State highways. This RDI data provides planners and designers with a general, but objective measure of out of direction travel requirements for a reference trip. The data is best suited for analysis of pedestrian and bicyclist trip making at regional or statewide scales. This layer uses available network input data and does not capture all potential crossing locations or evaluate the suitability of a given crossing for active travel. |
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Washington State Department of Transportation |
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5000 |
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[] |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This feature class represents the routes that were used for the Route Directness Index calculation. These routes were generated by submitting the begin and end points of each RDI_Transect to the Esri routing service with a Walking travel mode. The service returns a route of the shortest pedestrian path between the two points. The routing service is dependent on the Esri network data available when the service was accessed in June 2022.</SPAN></P><P><SPAN><SPAN>The Route Directness Index (RDI) is a ratio that compares the straight-line (crow-flies) distance across a barrier and between two points to the actual distance imposed by the network of paths available to a traveler. RDI data is particularly relevant to pedestrian and/or bicyclist trips due to the extra time, physical energy, and exposure to weather out of direction travel creates. Research indicates that pedestrians are especially sensitive to out of direction travel and Broach, 2016, found that "to avoid an additional unsignalized arterial crossing, a pedestrian would be willing to go over 70 meters (230 feet) farther via an alternate path." This finding suggests that route directness is relevant to considerations of both utility and safety with respect to active travel. A complete discussion of route directness, including potential applications to decision making, can be found </SPAN></SPAN><A href="https://wsdot.wa.gov/sites/default/files/2021-11/MultimodalPermeabilityPilotReport-Aug2021.pdf"><SPAN><SPAN>Washington State Multimodal Permeability Pilot, August 2021</SPAN></SPAN></A><SPAN><SPAN>.</SPAN></SPAN></P><P><SPAN><SPAN>RDI can be analyzed at different scales. A high-level analysis of RDI can address questions that compare population centers across the state or consider whether the RDI values are generally similar within a given population center or tend to vary in different portions of a population center. High level data could be combined with other statewide data such as crash data, transit stops, level of traffic stress data, destination data, etc. to analyze potential correlations. High level RDI data is less useful for analyzing a particular crossing location or recommending solutions to address high RDI values. A more detailed analysis is likely required when questions involve corridor studies or project evaluations. Detailed location information can refer to key destinations and crossing locations that are not captured using higher level network maps.</SPAN></SPAN></P><P><SPAN>The lowest RDI is 1 because a trip between those points can be made directly along an existing roadway. The actual methodology analyzed hypothetical trips where the start and end points were about a quarter mile apart relative to a straight line. In such a situation, an RDI of 2 would mean the trip is twice the distance it might otherwise be, or about one-half mile. Although one-half mile is not particularly far, the RDI is independent of the actual distance. We might start further down the road and if the RDI remained a 2 our trip distance would be twice as long as it could have been. The RDI thus measures the real or perceived burden or travel cost incurred by a person walking or bicycling. An RDI of 2 was selected as the threshold where that travel cost makes it increasingly unlikely that an active travel trip would be completed. The “design vehicle” when selecting that threshold was a walking pedestrian. Selecting an RDI of 2 was an attempt to balance observed travel behavior and the realities of existing crossing opportunities along the state highway system. In addition, since this analysis used about a quarter-mile spacing between test destinations, an RDI of 2 corresponds to the one-half mile maximum distance transit planners assume a pedestrian will be willing to walk to catch a bus or train. (FHWA, Pedestrian Safety Guide for Transit, 2013) So with respect to multimodal trips, RDIs greater than 2 might make transit less attractive.</SPAN></P><P><SPAN /></P></DIV></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>For planning use only. </SPAN><SPAN><SPAN>The Washington State Department of Transportation shall not be liable for any activity involving these data, including, but not limited to, lost profits or savings or any other economic or consequential damages. Nor does the Department warrant the fitness of the data for use for a particular purpose, or the installation of the data, its use, or the results obtained.</SPAN></SPAN></P></DIV></DIV></DIV> |
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RDI_Routes |
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["Route Directness Index","Permeability","Active Transportation","WSDOT","WA","DOT","Washington","State","Department","Transportation"] |
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en-US |
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150000000 |
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