In 1896, after one of the earliest recorded deaths of a pedestrian in a motor crash, the coroner in London reportedly said, “This should never happen again.”
More than a century later, 13 lakh people lose their lives each year in road traffic crashes across the globe. India has one of the worst road traffic records in the world, with 1.5 lakh people losing their lives to crashes every year.
Cities such as Bogota, Mexico City and Sao Paulo are working to reduce traffic crashes by doing things differently. They are successfully reducing fatalities by embracing the Safe Systems Approach, which looks at road safety from a different perspective.
Here, the onus of a crash does not lie only with those using the infrastructure – drivers, pedestrians, cyclists and others – but also with those involved in the design and implementation of streets: engineers, policymakers and designers.
City streets should have the structural ability to carry the traffic load, while also enable the safe and efficient movement of vehicular and pedestrian traffic.
Indian streets, typically, only focus on the former. Across India, there are always more citizens walking, cycling and riding two-wheelers than those traveling in cars. In Mumbai, for instance, 51% of the total daily trips are on foot.
As India urbanises rapidly, it has become imperative to focus on street design as a science that involves not only civil engineers but also urban designers and traffic engineers.
Traffic engineering
Traffic engineering employs techniques to achieve the efficient movement of citizens and goods on streets. These techniques include developing standards for road geometry, sidewalks, crosswalks, cycling infrastructure and traffic signs while also ensuring their implementation.
Traffic engineering largely focuses on three critical principles:
1. Design speed: This is the target speed at which drivers are intended to travel on a street, and not, as often misinterpreted, the maximum operating speed. This can be based on the number of citizens walking on the street, the vehicle counts as well as the degree to which travel modes are mixed or separated. Getting design speed right is critical since speed is also the primary factor in the likelihood of a crash. An increase in the average speed of just 1 km per hour results in a 3% higher risk of a crash and a 4%-5% increase in fatalities. Roads can be designed for lower speeds by providing frequent pedestrian crossings, limiting the number and width of lanes, using low speeds for turn radii, and introducing trees and other street elements such as seating and safe and engaging waiting areas.
2. Traffic conflict: This is an event involving two or more road users, in which the action of one causes the other to manoeuvre to avoid a collision. Traffic conflicts can be reduced through speed management and by providing the right infrastructure that does not put pedestrians in conflict with vehicles in the first place.
3. Shock waves: Every time a traffic conflict occurs, a shock wave is created. This causes a ripple effect in the traffic flow, slowing down vehicles for at least 50 metres downstream, depending on the speed of the vehicles, also commonly called traffic jams. Providing adequate space for pedestrians and designing for lower speeds improves traffic flow by limiting the frequency of shock waves.
Why design for pedestrians?
Most citizens walk to work, school, the market or to the nearest public transit mode. Students are said to walk the most. In Delhi, 58% of all educational trips are done on foot. Cities must start counting these pedestrians and design streets for them.
- Design for walking: WRI India has developed an algorithm that can count pedestrians from images or video feeds. Designing streets that provide adequate spaces for pedestrians to safely walk, stop and cross a street reduces conflicts that slow down traffic while making walking safer.
2. Designing for pedestrians improves overall efficiency: The algorithms also enable the identification of crash or conflict points from video feeds.
Image one (below) shows the number of conflict points before interventions were introduced to effectively manage the intersection.
Image two (below) shows how elements such as a refuge island, a median and tighter curb radii reduce conflicts and improve the traffic flow.
This indicates how providing pedestrian infrastructure reduces the number of conflicts and can improve the existing street scenario for all road users.
A WRI India pilot project in 2017 at Mumbai’s HP Petrol Pump Junction in Bandra saw the number of lanes and their width being standardised. This, coupled with the inclusion of pedestrian-infrastructure, lowered conflicts, improved traffic flow by 20% and also improved accessibility for all street-users.
It is pertinent to start considering streets as critical assets for both the city and its residents.
Safer and inclusive streets encourage more citizens to walk, cycle and use public transport. This not only smoothens traffic flow, but also helps lower carbon emissions and improve health. By changing the way we design streets we can strengthen our climate commitments and humanise our cities.
Madhav Pai is the Executive Director, World Resources Institute, India (WRI India) Ross Centre and Dhawal Ashar is the Head, Integrated Transport at the same organisation.