Nik Hunder is an environmental policy analyst, researcher, and public transit advocate based in Chicago. He’s previously written for A City That Works about the skyrocketing costs of the CTA’s Red Line Extension.
Chicago has a pretty excellent bus network, with 127 routes covering the City’s tightly laid-out grid structure. In 2024, the bus network accounted for 58% of the total trips on the system.
But while there’s a lot to like about our buses, they stop far too often. Those 127 routes have more than 10,500 stops. Some stop at nearly every block (1/8th of a mile). Some stop even closer than that – within just 200 feet of the previous stop.
This hyper-local stop pattern is a good-faith effort to ensure that any given rider is no further than a five-to six-minute walk away from a bus stop, but every additional stop slows down the bus for every other rider on the line. It’s nice to have a bus stop right outside your door, but that bus is a lot less useful if it moves at a crawl thanks to ever-present stops which increase dwell time. It’s also at odds with national and international best practices. As Richard highlighted a few weeks ago, Chicago has the most tightly-packed bus stations of any City in the country.
Source: Pandey et al, 2021
Bus Stop Spacing Distribution Comparison. Visualization inspiration by: Logan Williams Visualization by Nik Hunder. Data by: CTA, MTA, and LA Metro
But while it’s one thing to highlight this issue, it’s quite another to decide which stops to remove. The interactive map below shows how CTA could remove 41% (4,360) of its 10,511 in-service bus stops to align with national best practices while still meeting federal requirements in Title VI of the Civil Rights Act of 1964 and the Americans with Disability Act (ADA).
Screenshot from the interactive bus reduction model covering the Loop and Near West Side. Green stops are removed, black stops are kept. Source: Nik Hunder.
You can (and should) view the full visualization here. Unfortunately, Substack does not allow it to be directly embedded in the article.
Why “this” stop should be removed
It’s quite an undertaking to make individual choices about 10,551 bus stops. CTA often spaces its stops with the same consistency thanks to Chicago’s remarkably consistent grid. Because of this consistency, part of this process included creating a decision tree algorithm in R that compared the distance between stops to iteratively decide whether the stop should remain or be taken out of service. The primary factor was the distance between two stops. The decision tree primarily sorted stops by suggesting a stop gets removed if the distance between two stops would be between 1200-1450 feet (~400m) if stop “X” were taken out of service. All decisions by the algorithm were manually reviewed.
There were good reasons for keeping a stop even if it meant that the bus would create an every-block stopping pattern for a half mile. Reasons for keeping a stop included:
It is a transfer to another bus, L line, or Metra train
It was in the 90th percentile of the route’s ridership
It served a critical service like grocery stores, social services, hospitals, or other uses that would be more likely to serve passengers with disabilities
It might be expected that a reason for removal was that the stop had no cross street or just an address. These are common in industrial or less dense areas of the city. Ridership is usually in the bottom 10% of all stops which is actually a good reason for not removing them. Since so few people board here, stopping there once or twice per day to allow someone an easier walk to their destination has no sizeable impact on slowing the bus down. Instead, removing stops where another is nearby are the ideal stops to remove as it causes riders to move no more than 1/8 mile (2 minutes) down the route.
Chicago’s consistent grid spacing means that each use of a given road between two major blocks is predictable. It typically goes: arterial, residential, minor arterial, residential, arterial (figure 2). Residential roads are hyper-local by national standards and are the primary form of stop removed in this visualization. Based on CTA’s estimated boarding/alighting data, residential stops account for 19% of ridership but make up nearly 39% of all stops on any given route. This imbalance is a culprit in slowing the bus down.
This regular grid spacing is helpful in many ways, but it does mean that Chicago can’t pick any distance between stops for regular spacing: we’re basically choosing between stops 1/8th of a mile apart and 1/4th of a mile apart. That’s probably part of why the stops are so densely spaced now – we’d have to double our current average distance between stops, which feels like a dramatic jump. But making that jump would have a lot of benefits for riders and the system as a whole.
Bus stop spacing frequency of Cincinnati Metro’s FAStops program. Source: Cincinnati Metro
Realistic speed increases
The bus spends its time doing one of four things: moving, boarding/alighting passengers, being stuck in traffic, or waiting at a red light. This is to say that reducing bus stops will not suddenly speed up the bus by 40% in the same way that transit signal priority or a painted bus lane cannot do it individually either. Rather, it is an overlooked tool in the chest.
Chicago’s express buses provide a glimpse into what reduced stop spacing does for bus speed. As you can see in the chart below, the CTA runs express service on the X4, X9 and X49 from 4a to 10p - during which the buses stop only every half mile. The express lines run at an average speed of 11mph between 6-10a and local equivalents moved at an average speed of 9.2mph. During the midday hours of 11a-3p, the express buses efficiency averaged 10.5mph while the local buses slowed to an average of 8.4mph. The difference in speed is even greater outside of peak travel hours, reaching up to 4mph quicker.
CTA Express Bus (X4, X9, X49) versus Local Bus (4, 9, 49, 49B) average Weekday Travel Speeds. Data: CTA. Data scraping: Daniel Cruz. Data visualization: Nik Hunder
Eliminating stops would functionally turn every other bus lane into a semi-express bus. Based on the data from the express buses we do have today, that could translate into speed improvements of 14-29% depending on the route, traffic levels, and how many stops are removed. That’s a remarkable increase in speed, at minimal cost to the agency. If a rider’s walk increases from two to five minutes but gets them to their destination more than three minutes quicker, it’s an easy sell.
There are other benefits as well. Fewer and more regular stops make bus travel times more regular, which helps keep buses on schedule and reduces bus bunching. And faster buses also make CTA bus operators more productive. A bus that’s 20% faster requires 20% fewer labor hours to cover the same route. That would help the agency control operating costs or deliver more service with the same budget.
Adjusting bus spacing has initial costs but over time it saves money. Upfront, workers need to remove and update signage, change digital brochures, consolidate a small number of bus shelters, and perform public outreach. This all pales in comparison to the increase in long-term benefits such as a regional GDP increase from faster travel times, shorter headways provided with the same number of labor hours (or labor savings) and state-of-good-repair costs decrease because of less damage to pavement.
The CTA would not be the first transit agency to do this. Many transit agencies since 2000 have undergone a rebalancing effort, including New York’s MTA, Denver’s RTD, Seattle’s King County Metro, and Cincinnati Metro. They all found that through public outreach and learned communication strategies, a majority of riders wanted and were satisfied with the reduction in stops because the bus was faster.
Federal and ADA requirements for bus spacing
Federal and ADA
There are no specific bus spacing standards or ADA spacing standards issued by the federal government. Instead, transit agencies are granted flexibility to create their own standards as long as they comply with Title VI of the Civil Rights Act of 1964. The Federal Transit Administration (FTA) simply requires that agencies define and post their service standard metrics which include: headways, vehicle load, and transit amenity availability. As long as the agency does not discriminate in allocating its resources, they are in compliance with Title VI. You can view the CTA’s service standards here.
For concerns about accessibility, the ADA requires paratransit service in areas where an agency offers a fixed route service. Paratransit service is available in the RTA service area during the same hours of service as its nearby fixed route.
American Public Transportation Association (APTA)
It is common practice for some federal agencies to defer to standards-making organizations. Here, the FTA defers to APTA for better guidance on service standards. At its most precise, APTA recommends using the spacing provided in Figure 1.
Transport Modes from APTA-SUDS-UD-RP-001-09
Most CTA buses fall into either local street or rapid street transit meaning they should be spaced between 1/8 and 1/3 mile apart. Local streets refer to routes like the 44, 50, and 96. Rapid streets are similar to the 49, 63, or 95. Currently, almost all routes utilize 1/8 mile spacing. This proposal increases all routes to between 1/4 and 1/3 mile. The only routes that already met this standard were the X4, X9, and X49. Even CTA’s neighborhood-to-neighborhood express routes like the 2, 6, and lakefront express buses use 1/8 mile spacing, which is sometimes as small as 1/16 mile. If CTA decides to invest in bus rapid transit (BRT), not simultaneously adjusting stop spacing would bring it out of compliance with APTA recommendations and fail to realize its full potential.
Catchment Areas
Another concern with reducing stop frequencies is reducing how many potential riders can be lost by reducing the catchment area (pictured below), the area of influence where characteristic of the surrounding area influences whether a potential rider is likely to select transit.
In this example, since most of CTA service is local street transit, APTA defines the primary catchment area as radius (r’) = 1/8 mile and the secondary catchment area as r’ = 1/2 mile. By removing the residential stop, the secondary catchment area decreases by 0.2% and the primary catchment area by 10%.
Both of these are minor changes by comparison because the decrease in the primary catchment area becomes part of the secondary catchment area where the investment in pedestrian and bicycling infrastructure can still generate a return on investment. The main difference between primary and secondary is whether a potential customer may require a secondary mode of travel to access the stop. Riders can expect the impact to be minuscule with an insignificant amount of secondary catchment area being removed.
The presence of geographic features and vehicular infrastructure has a much greater impact on ridership than bus stop reduction (figure 5). The former greatly reduces the catchment area and has been well documented as causing lasting harm to communities during urban renewal in the post-WWII period. Additionally, the same geographic and vehicular infrastructure is more influential to a catchment area than slightly reducing accessibility through stop rebalancing.
The presence of micromobility features increases the primary catchment area (figure 6). Chicago is one of the first cities in the nation with a proposal to build out a complete bike network that would complement the bus network and expand the primary catchment area.
Political challenges
The benefits of stop consolidation are well known across the industry. The challenge is that no one wants *their* stop removed. And because Aldermen are incentivized to prioritize hyper-local concerns but still wield control over CTA board appointments, individual complaints quickly translate into service that’s worse for everyone.
These politics are difficult, but they might be about to get a little easier. Under the new Northern Illinois Transit Agency, service standards and route planning will be handled by the regional agency, rather than the CTA. And a majority of the CTA’s board will no longer be picked by the Mayor (and appointed by the City Council). That reduces the level of control alders will have over the process, and might make it possible for a regional body to start to push through a higher-functioning route plan.
Of course, the CTA’s still going to hear criticism. And the City Council will still be able to exert significant influence over the agency – including by withholding TIF dollars for new capital projects.
But rather than hanging back and doing nothing, the CTA should put an ambitious proposal on the table and then let the chips fall where they may. At a minimum, we’re much better off identifying the source of our political dysfunction, rather than continuing to operate like there’s no problem here to begin with.
Getting it Right
The interactive map included with this post is a place to start, not an evaluation of who is worthy enough to keep their bus stop (I removed four of my closest stops). It aims to provide a framework for consistent decision-making using the same criteria system-wide to make everyone’s trip faster and reduce headways with minimal investment.
With $1.38B in new funding coming in Winter ‘26, it’s time for the CTA to look beyond doing more of what it was already doing. This is one of many ways the CTA could leverage new money to go even further and deliver higher quality service at better value for riders. A win for most should not be disrupted by an upset minority. Make like other transit agencies and innovate in the face of resistance.
I didn't write extensively about my method (boring to some), but I'm happy to answer questions about contributing resources and decision tree design.
I found a job opening for Nik at CTA: “Director, Policy”
https://chicagotransit.taleo.net/careersection/exm/jobdetail.ftl?job=2500008Y