John Schoon, the author of Pedestrian Facilities: Geometric design for safety and mobility, Second edition, shares some of the current challenges of designing for pedestrians and gives insights into solutions.
Designers at all levels - in policy development, professional, technical and academic - are key to improving pedestrian facilities and enhancing the safety and convenience of walking. This is a challenge when nearly five hundred pedestrians are killed in the UK every year and nearly 4,500 are seriously injured. The UK has the highest ratio of pedestrian to all road casualties in western Europe. Potentially contributing to these statistics are deficiencies which practitioners encounter daily. They exist in engineering education; inconsistency between Highway Code and design; poor design layout; and misrepresentation of pedestrian cognition and physical characteristics.
Recently proposed and extensive government investment for transport, features minimal improvements for pedestrians. Yet pedestrian access is essential for all modes of transport. For example, an improved bus service will be less effective if passengers, especially disabled ones, cannot safely and conveniently get to a bus stop. Fostering walking needs to be an essential element of planning for multi-modal travel.
Most designers of roads (including footways) undertake courses which consider speed, acceleration, deceleration, driver reaction times and sight distances – all fundamental parameters of physical design and vehicle trajectories. Yet similar characteristics of pedestrians in their interaction with vehicles are not addressed to the same extent. For example, pedestrian gap acceptance for crossing a carriageway is usually based on a sample of observed pedestrian behaviour. But this ignores disabled or encumbered people, who may not cross at all because of dangerous vehicular traffic, distorting safe crossing assumptions. Another example is where the designer of a junction is advised to consider the actions of a driver negotiating the junction, but not of a pedestrian negotiating it.
The Highway Code
In many respects the Code and design practices are not coordinated. For example, when approaching a roundabout, drivers are advised to look to the right for approaching vehicles, but they are not advised also to look to the left for pedestrians who may have started to cross. The Code emphasises drivers’ needs such as ‘watch out for pedestrians crossing a road into which you are turning. If they have started to cross, they have priority so give way’.
Designs which ignore this advice can result in
refuges too far from junctions
excessive corner radii
limited pedestrians’ sight lines
absence of appropriate markings
barriers resulting in tortuous pedestrian crossing routes.
No consideration is given to pedestrians who have to cross behind waiting vehicles at the ‘triangle’ markings of a junction, and so may be unseen by turning drivers.
Pedestrians need to move along the desired route safely and conveniently, but current design does not include pedestrian’s sight distances, which in turn depend on pedestrians’ reaction and complete crossing times. At any likely crossing point, the details of the crossing configuration (either at a junction, mini-roundabout, or at some other key point) are based on drivers’ sight distances and their ability to stop if a pedestrian is crossing. The pedestrians’ sight distances are not included. This can prevent them from judging if the driver is stopping, slowing, speeding or simply not seeing the pedestrian. The pedestrian is, therefore, totally dependent on the driver’s behaviour to ensure a safe crossing. Since most collisions are caused by drivers reportedly failing to see, this is clearly a deficiency in the design process and the stopping sight distance should also depend on the pedestrian’s sight distance to an approaching vehicle.
Misrepresentation of pedestrian characteristics
Pedestrians’ crossing times are currently based on a constant speed of an infinitely thin entity crossing between kerbs. Ignored are an actual entity’s (single, accompanied or encumbered pedestrian) distance behind the starting kerb, its length, an adequate start-up time, acceleration and deceleration speeds, and delays at the far kerb or lip of a dropped kerb. Disabled or encumbered people are particularly prone to these characteristics. When considered, these concerns can add up to 50% or more of the crossing time needed from current design norms. Acceptable values for crossing times, therefore, need to be urgently established for specific categories of pedestrians.
Societal and environmental issues
From a legal and societal perspective, many elements of pedestrian facilities are deficient. For disabled people they clearly do not comply in many respects with the 2010 Disability Act, which requires equivalency with facilities for the general population. This latter requirement means that more than 12% of the population (plus others such as school children) must rely on motorised transport for safe movement, exacerbating economic, health, wellbeing and environmental problems.
The way ahead
Designing improved pedestrian facilities requires awareness of the issues described above, along with day-to-day design for maintenance and new facilities. My recently released book, Pedestrian Facilities: Geometric design for safety and mobility, Second edition, presents basic principles and officially documented guidance related to such principles, assisting the designer in exercising professional expertise and judgement in improving this vital element of our multi-modal transport system. The active involvement of practitioners at all levels is pivotal to this process.
Find out more about Pedestrian Facilities: Geometric design for safety and mobility, Second edition, authored by John Schoon, available in print and as an eBook.