What is this?
A map showing the walkability catchment area of one point in Downtown Pittsburgh, as defined by the street grid. This is a common tool used in transit planning and placemaking to determine the walkability of an area and demonstrate how far away the site is to any other destinations or amenities. The easy way to do this is to draw a quick ¼-mile or ½-mile radius around a site, and the output is a rough guide to how far a pedestrian can walk in the allotted time. But Pittsburgh’s unique topography, inconsistent street grid, and long bridges make it impossible to walk “as the crow flies”-- you can see the noticeable difference in the two approaches in the image above. We decided that we had to go further and find out precisely how well pedestrians move between locations downtown.
The usefulness and accuracy of this analysis relies on two basic assumptions: one, a pedestrian must follow the available roadways when walking to their destination; and two, it takes a pedestrian about 5 minutes to walk ¼ mile (assuming an average speed of 3mph). With that in mind, we began building a pedestrian network that approximated pathways throughout the city, eventually using GIS to give us an idea of how far someone can get from our chosen locations by following the available pathways.
Image Explanation (L to R):
FIG 1. First, we identified a few places that we determined were hot spots for Downtown. A radius was added for each at the three specified steps of ¼, ½, and ¾ miles, which shows us the furthest extent the network can reach.
FIG 2. The next step was to begin building our pedestrian network in ArcGIS by modifying the publicly-available street grid provided by the City of Pittsburgh DCP, taking away highways and adding public stairs, trails, and cut-throughs. For the sake of time and simplicity we went ahead and drew the pedestrian paths down the middle of the street when the sidewalk was available on both sides. NOTE: The image in Fig. 2 was partially completed at the time it was taken.
FIG 3. Once the network was built we specified the creation of three radii from our original origin points: 5, 10, and 15 minutes away (¼, ½, & ¾ mi). The output is processed through GIS software, and the resulting information is combined to give a good sense of walkability in the area. Particularly in this image, the impact of the rivers on inter-neighborhood mobility is apparent.
Following this last step we were able to create our own "ped shed" of the total possible area a pedestrian could get to using our parameters, the final results of which are shared below.
We specified different points of interest in the Golden Triangle in order to assess how well-connected they were to their surrounding areas. The outdoor plaza of Market Square boasts the largest average concentration of pedestrians in Downtown according to the Public Space-Public Life Survey conducted last year. Because so many people arrive and depart from the space throughout the day, it began as the basis of our walkability analysis.
Other locations we chose as hubs for pedestrians were: David Lawrence Convention Center, PNC Park, and Point State Park, and the City-County Building, all shown below:
What can we learn?
These maps show a Central Business District that is compact and easily traversable, but without many good connections to the rest of the city. Bounded by the rivers to the north and south and highways to the east, a pedestrian only has the option of passing through a limited number of transition points to reach other parts of the city. One of the most important connective pathways is the trail system, which extends along and across the rivers and allows easy passage between neighborhoods. Making stronger connections between the trails and the rest of the street grid should be a priority moving forward.
The Golden Triangle is dense, with two colliding linear street grids and non-uniform buildings of different heights and square footage—to the average visitor, it can feel larger than it actually is. These maps show that walking can, and should, be a practical way of navigating the downtown area. Market Square to PNC Park in 10 minutes, the Convention Center to the Strip in 15 minutes; these are just a few examples of the linkages that make up a valuable part of the Downtown network. When the pedestrian is prioritized as an equal player in the urban space, more people will be invited to make these short trips on foot, connecting economic assets and providing utility for residents and visitors alike.