Catchment areas

Getting serious about the walking experience to maximize public transport investments

Article by Charlotte Hauri – 09 December 2024

Looking more closely at the fundamental qualities of pedestrian access to public transport, recent research has clarified some of the more subjective factors of walkability that comprise the walking experience. It has been shown that the walking experience significantly impacts riders’ overall public transport experience and influences their decision to use public transport or not. People have been shown to be willing to walk almost twice to public transport as far in pedestrian-oriented environments – substantially increasing potential public transport ridership (i).

Connecting the walking experience with walking behaviour

While perceptions and sensory experiences are subjective, there are helpful frameworks from which to base evaluations. Ewing and Handy provide a framework that illustrates how the physical environment and human perception influence walkability and our walking behaviours (ii).

Perceptions of time while walking 

Our perception of time influences our decision to use public transport or not – if we think it will take too long to walk to public transport, we may opt for another mode of transport altogether. Influenced by the physical environment and individual sense of safety and comfort, perceived walking times can be difficult to measure. But a couple of key things we do know are:

1. People are just not very good at estimating the distance or time to walk somewhere, and we have the tendency to overestimate (iii).
2. Short stimulating activities are shown to leave us with bigger memory impressions than long and boring activities (iv).

Hillnhütter found that the perceived time spent walking through a pedestrian-oriented area with shops and buildings with interesting facades result in 26% longer accepted walking distances than along a boring street lined with large scale buildings with closed façades and few pedestrians (v).

To make such findings actionable in public transport planning, our UPPER colleague, UITP and Walk21 highlight a few strategies in their recent policy brief to reduce perceived walking times:

• Prioritize people walking in street design
• Review crossings to limit the barrier effect of car traffic
• Increase possibilities to access shops and services
• Identify preferable walking routes and effective footpath networks that are direct and convenient (vi)

How do you identify and promote preferable walking routes? There are several traditional and digital strategies, namely:

• Wayfinding – Serving as point-of-decision cues, wayfinding signs can change walking behaviors by:
  • Providing directions to a destination
  • Clarifying how long it takes to walk there (vii)
• Mobility as a Service (MaaS) platforms – MaaS platforms, like Google Maps or those developed by public transport authorities, can be used for individuals travel planning purposes or by a public transport authority. To promote pedestrian access, MaaS platforms should:
  • Put walking at the top of the hierarchy and exploit nudging messaging (viii)
  • Include individualized user profiles to gather user data and, in turn, tailor messaging (ix)

Human emotions while walking

To develop definitions to measure the physical environment and to test for significant associations with walking behaviors, Ewing and Handy found that physical characteristics of the street environment impact people’s perception of walking. For example:

• Noise negatively impacts perceptions of walking
• Windows on first floor façades positively impacts perceptions of walking (x)

By investigating head movements to show stimuli in different physical environments, Hillnhütter found that socially active pedestrian areas with shop windows can raise stimulation levels by about 70 – 90%, compared to surrounds with large-scale buildings, monotonous façades, and wide streets (xi). By plotting such findings onto a circumplex model (below), he offers a clear illustration of the way in which physical environments influence the emotions of people walking, as well as the experience they have walking (xii).

While our reactions and experiences while walking are not uniform, this model is telling. Findings from other studies, like Golan et al., which explore women’s subjective pedestrian experiences, are not dissimilar either. Golan et al. conclude:

• Fear of crime was the top consideration for women when deciding to walk
• Street and sidewalk cleanliness and traffic volumes were the most influential factors after perceived security
• Streets and building designs should encourage “eyes on the street” and minimize the number of deserted spaces
• Traffic calming, including a better separation between cyclists and pedestrians; removing large off-street parking lots; and adding greenery and shrubbery to urban streets and sidewalks could enhance walkability for women (xiii)
  

While we highlighted more subjective—but also strong emotional—factors here that affect people’s perceptions of walking to and from public transport, infrastructure also plays an important role. Are you surprised by what you see in in Hillnhütter’s model or by the factors that impact women’s walkability? We aren’t.

The evidence is clear: To maximize our investments in public transport, we must also focus on walkability – we must design streets that make people feel safe, secure, and comfortable walking. Only after we get serious about the walking experience, and our policies and investment decisions reflect that, will we be able to realize the potential of public transport.

All footnotes below

Hillnhütter, “Pedestrian access to public transport,” 38 – 39. Ewing and Handy, “Measuring the unmeasurable: Urban design qualities related to walkability,” 67. Ralph et al., “Is it really too far to walk? Overestimating walk time and distance reduces walking,” 533. Hillnhütter, “Pedestrian access to public transport,” 65. Hillnhütter, “Pedestrian access to public transport,” 171. Walk21. “Integrating Walking + Public Transport,” 7. Ralph et al., “Is it really too far to walk? Overestimating walk time and distance reduces walking,” 533. Madigral et al., “Pedestrian mobility in Mobility as a Service (MaaS): sustainable value potential and policy implications in the Paris region case,” 11. Pangbourne et al., “Persuasion profiles to promote pedestrianism: Effective targeting of active travel messages,” 311. Ewing and Handy, “Measuring the unmeasurable: Urban design qualities related to walkability,” 67. Hillnhütter, “Pedestrian access to public transport,” 182. Hillnhütter, “Pedestrian access to public transport,” 175. [1] Golan et al., “Gendered walkability: Building a daytime walkability index for women,” 523.

Giving catchment areas a reality check: Incorporating walkability into transport planning

Article by Charlotte Hauri – 11 November 2024

Catchment areas have long been fundamental to public transport planning and evaluation, with a circular catchment area—or straight-line buffer approach—being the simplest. The assumption has been that people are willing to walk between 400 and 800 meters to reach a transit stopⁱ. By relying on a 400-meter radius around a public transport stop, however, it assumes that there is equal walking access throughout the radius, and the level of detail does not always consider factors that affect access to the public transport stopⁱⁱ. Unsurprisingly, this method quickly falls short of reality – catchment areas need a reality check.

Using analysis tools and data

Circular catchment areas, calculated using the straight-line approach, have been shown to consistently overestimate population access to public transport stops and, thus, the walkability of the urban environment and the physical abilities of the person walking along the wayⁱⁱⁱ. Instead, analysis tools and data can be used to better capture the complex context of the urban environment and better represent pedestrian access to transport stops: 

• Geographic Information Systems (GIS) can be used in a high level of detail to refine circular catchment areas^iv
• OpenStreetMap datasets can be used as it offers representation of walking and bicycling^v
• Isochrone maps can be used to correct walking distances by considering walking times^vi

Incorporating the pedestrian environment 

To incorporate the pedestrian environment, catchment areas can be refined by incorporating the physical environment. To start, incorporate key walkability information, such as:  

• Existing footpath networks  
• Detour information  

Existing footpath networks

By incorporating existing footpath networks into catchment area analyses, public transport planners can better calculate real walking distances to transport stops^vii. David Vale, for example, uses 83 transport stations in the Lisbon metropolitan areas to show how pedestrian access compare 700-meter circular catchment areas.  

To calculate pedestrian access—or “pedestrian shed”—Vale used OpenStreetMap data and ArcGIS Network Analyst 10.2. Existing footpath networks were calculated for each site by: 

1. Removing non-pedestrian segments (highways, etc.)  
2. Crossing-referencing Google Earth satellite imagery for accuracy 

 Pedestrian shed ratios of the 700-meter radii were calculated using ArcGIS Network Analyst 10.2. The resulting pedestrian sheds illustrate how much the physical environment impacts pedestrian accessibility to public transport and how insufficient theoretic catchment areas can be^viii.   

Detour information

Willingness to walk has been shown to sharply decline for trips longer than 400 meters. As such, more direct routes with smaller detour factors can increase willingness to walk to public transport^x. By incorporating walking detour information—which represents the time difference between walking a straight-line path and the actual distance someone must walk—into public transport planning, initial walking distances can be corrected^xi. Detour factors can be calculated by dividing the actual distance by the straight-line distance^xii. As a rule of thumb, detour factors should be as low as possible. Generally, between 1.0 to 1.25 is considered acceptable^xiii.  

 Isochrone maps also can be used to answer the question, “How far can someone walk to this transport stop in x amount of time?”^xiv. While ArcGIS tools can be used to produce isochrone maps^xv, private companies, like EPB Schweiz AG, have developed pedestrian isochrone maps, making them much more accessible^xvi. These maps consider the physical context—such as topography and pedestrian short cuts through parks—to more accurately show walking times. 

Additional considerations

Beyond the physical environment, there are other variables that significantly impact pedestrian access. Physical ability, safety and security, as well as weather, for instance, all impact public transport access and should be considered in public transport planning as well^xvii. 

Physical abilities

Walking times to public transport stops has as much to do with the physical environment as it does with the physical abilities of a person walking. Alves et al. summarize estimated walking speeds found in various studies, which shows a range of estimated walking speeds across age groups: 

• <30 years of age: 1.34 m/s 
• >65 years of age: 0.60 – 1.00 m/s^xviii 

 For public transport to be accessible, walking speeds—and ranging human physical abilities—must be closely considered.

Safety and security

Whether it is exposure to theft, harassment, unsafe driving behaviors, unsafe waiting areas, or fear of not knowing how to use the transport system, people consider such potential hazards when choosing to use public transport^xix. When considering safety and security and pedestrian access to public transport stops in planning, Jehle et al. provides helpful criteria: 

Weather

While weather may not always be shown to influence the decision to walk to public transport, it undoubtedly impacts the experience of walking of walking to public transport^xxi. Physical design choices can counter weather and improve walking experiences despite it^xxii. Walk21’s top recommendation for achieving and integration of walking in public transport is to provide infrastructure to protect against weather conditions^xxiii. The placement of such infrastructure should be a planning consideration to improve the experience of walking to public transport.

All footnotes below

Canepa, “Bursting the bubble: Determining the transit-oriented development’s walkable limits” 28. Andersen and Landex, “Catchment areas for public transport,” 183. Horner and Murray, “Spatial representation and scale impacts in transit service assessment,” 794. Andersen and Landex, “Catchment areas for public transport,” 183. Gil, “Building a multimodal urban network model using OpenStreetMap data for the analysis of sustainable accessibility,” 235. Hillnhütter, “Pedestrian access to public transport,” 25. Hillnhütter, “Pedestrian access to public transport,” 25. Vale, “Transit-oriented development, integration of land use and transport, and pedestrian accessibility: Combining node-place model with pedestrian shed ratio to evaluate and classify station areas in Lisbon,” 73. Vale, “Transit-oriented development, integration of land use and transport, and pedestrian accessibility: Combining node-place model with pedestrian shed ratio to evaluate and classify station areas in Lisbon,” 76. Meeder, “Detour factors in pedestrian networks,” 2. Hillnhütter, “Pedestrian access to public transport,” 25. Hillnhütter, “Pedestrian access to public transport,” 23. Berg, “Gestaltung von Zugängen zu den Haltestellen von Bahnhöfen,” 62. Dovey et al., “Isochrone mapping of urban transport: car-dependency, mode-choice and design research,” 402. O’Sullivan et al., “Using desktop GIS for the investigation of accessibility by public transport: an isochrone approach,” 85. Heuel, “Pedestrian Isochrone Maps.” Dovey et al., “Isochrone mapping of urban transport: car-dependency, mode-choice and design research,” 411. Alves et al., “Walkability index for elderly health: A proposal,” 4. Friman et al., “Public transport quality, safety, and perceived accessibility,” 2. Jehle et al., “Connecting people and places: Analysis of perceived pedestrian accessibility to railway stations by Bavarian case studies,” 4. Hillnhütter, “Pedestrian access to public transport,” 12. de Montigny et al., “The effects of weather on walking rates in nine cities,” 837. [1] Walk21. “Integrating Walking + Public Transport,” 7.