Findings: Shelter Equity

Summary

Only 7.3% of PRT bus stops have shelters, yet those sheltered stops serve 31% of total system ridership. Sheltered stops have 5x the median daily usage of unsheltered stops (34 vs 7 riders/day). The most striking gap is among regular bus stops, where just 7% have shelters despite serving the vast majority of riders. Several of the system's busiest stops -- including downtown intersections with 2,000+ daily boardings -- lack any shelter.

Key Numbers

• 6,719 unique physical stops in the pre-pandemic weekday data
• 491 (7.3%) have shelters; 6,228 do not
• Sheltered stops: median 34.3/day, mean 162.6/day
• Unsheltered stops: median 6.5/day, mean 28.9/day
• Sheltered stops serve 30.7% of total system ridership despite being only 7% of stops
• Mann-Whitney U test: p = 9.2e-84 (sheltered stops have significantly higher usage)
• Bus mode: only 7% sheltered; Busway: 73%; Light Rail: 100%

Observations

• Shelter placement correlates with usage but leaves major gaps. The top 20 unsheltered stops each see 1,200-2,800 daily riders. The busiest unsheltered stop (7th St at Penn Ave, 2,841/day) handles more riders than all but a handful of sheltered stops.
• Downtown Pittsburgh has the biggest equity gap. Almost all top unsheltered stops are in the downtown/Oakland corridor (5th Ave, Liberty Ave, Wood St, Stanwix St). These are high-exposure locations where riders wait in weather.
• PAAC and City of Pittsburgh own most shelters (197 and 174 respectively), with City shelters at higher-usage stops on average (204 vs 165/day).
• Lamar (advertising) shelters skew low-usage: 100 shelters averaging only 26 riders/day, suggesting ad-driven placement rather than ridership-driven.
• Heffner shelters also serve low-usage stops (avg 3/day), further suggesting non-ridership factors drive some shelter placement.
• "Envision Downtown" and "Other" shelters serve the absolute highest-volume locations (2,913 and 1,090/day respectively), but account for only 5 stops total.

Discussion

The shelter coverage gap represents a tangible rider experience problem. The 20 busiest unsheltered stops collectively serve ~35,000 riders per day who wait without weather protection. Given Pittsburgh's climate (Analysis 28 showed snow days and freeze days significantly affect OTP), shelter absence at high-volume stops compounds the negative experience of unreliable service.

The divergence between shelter owners reveals different placement strategies. PAAC and City of Pittsburgh place shelters at moderately high-usage stops (165-204/day), following a ridership-informed approach. Lamar's advertising-driven placements (26/day average) prioritize visibility for ad revenue over rider need, and Heffner's placements (3/day) appear driven by factors entirely unrelated to ridership. This suggests the advertising-shelter model, while providing free infrastructure, does not align with transit equity goals.

The Pareto finding from Analysis 34 (2% of stops serve 50% of riders) frames the opportunity: sheltering just the top 150 unsheltered stops would reach a large share of unprotected riders. At typical shelter costs of $15-30K per installation, covering the top 20 unsheltered stops would cost $300-600K while protecting ~35,000 daily riders -- a strong return on investment.

The downtown equity gap is particularly striking because these stops are the most visible face of the transit system. Visitors and new riders encountering a 2,800-rider/day stop with no shelter receive a signal about the system's investment priorities. Addressing the downtown/Oakland gaps would improve both rider experience and public perception.

Caveats

• The shelter field in the WPRDC data may not be fully up to date; some shelters may have been added or removed since the data was compiled.
• "No Shelter" is the default -- stops with missing shelter data are treated as unsheltered, which may slightly overcount the unsheltered total.
• Usage data is pre-pandemic (FY2019); current ridership patterns at specific stops may have shifted.
• Light rail shows 100% coverage but only 1 stop appears in the data, so the mode comparison is limited for rail.

Methods: Shelter Equity

Question

Are bus shelters equitably distributed relative to ridership? Which high-usage stops lack shelters, and does shelter coverage vary by mode or ownership?

Approach

• Aggregate pre-pandemic weekday ridership to the physical-stop level (summing across routes) to get total daily usage per stop.
• Classify each stop as sheltered or unsheltered using the shelter column; further break down by shelter owner.
• Compare median and mean usage between sheltered vs unsheltered stops (Mann-Whitney U test).
• Compute the share of total system ridership served by sheltered stops.
• Identify the top high-usage unsheltered stops (ranked by daily ons+offs) as priority candidates for shelter installation.
• Examine shelter coverage by mode (bus, busway, light rail) and stop type.
• Generate charts: ridership distribution by shelter status, shelter owner breakdown, and a priority list of unsheltered high-usage stops.

Data

Output

• output/shelter_equity_summary.csv -- per-stop summary with usage and shelter status
• output/unsheltered_priority.csv -- top unsheltered stops ranked by usage
• output/ridership_by_shelter.png -- box/violin plot comparing usage distributions
• output/shelter_coverage_by_mode.png -- bar chart of shelter coverage rates by mode