Pedestrian crossing

A pedestrian crossing, often called a crosswalk in North America, is a designated area for people to cross roads, streets, or avenues.

These locations are vital for managing the interaction between human movement and vehicle traffic. They are frequently placed at intersections or on busy roads where high vehicle speeds or widths make crossing unsafe. Engineers often install them in shopping districts where pedestrian density is high. They also protect vulnerable road users, such as school children, who cross regularly. In some jurisdictions, rules like jaywalking laws restrict people from crossing outside these marked areas.

There are several distinct types of crossings designed for different traffic needs. Zebra crossings are uncontrolled and feature black and white stripes on the road surface. These markings typically give pedestrians priority over vehicles. Pelican crossings are signal-controlled to keep pedestrians in a single group. This grouping makes them more visible to motorists and allows for safer movement through vehicular flow. Some crossings are multi-user, known as toucan crossings, which allow both pedestrians and cyclists to use them. For complete separation from traffic, cities may use pedestrian subways, which are tunnels under the road, or pedestrian overpasses, which are bridges above the road.

Designing these crossings involves specific engineering criteria to ensure safety. In the United Kingdom, engineers may use a prescription known as PV2 to decide on a crossing type. This formula uses the pedestrian traffic volume rate, P, and the vehicle traffic volume rate, V. By calculating the product PV2, planners determine the necessary infrastructure. For instance, if 500 pedestrians and 600 vehicles use a road per hour, the resulting PV2 is 1.8×10^8. This specific value dictates that a pelican crossing should be installed. However, some critics argue that an over-emphasis on vehicle movement can neglect pedestrian safety.

The history of signaled crossings began in London in December 1868. A railway engineer named John Peake Knight designed the first signal to help pedestrians, including Members of Parliament, reach the Parliamentary Estate. The device used three semaphore arms and a gas lantern that showed red and green aspects. A police constable had to manually rotate a handle to raise or lower the arms. Unfortunately, a gas leak caused an explosion in January 1869, which injured the operator. Because of this accident, no further work was done on signaled crossings for fifty years.

As car traffic increased in the early 20th century, the need for safety became a major public concern. By 1911, newspapers were reporting on the "fearful deaths" occurring on common roads. The rise of motor traffic meant that even a single hesitation could be fatal for a pedestrian. Later, on October 31, 1951, the first marked zebra crossing appeared in Slough, west of London. The name "zebra crossing" likely comes from the visual similarity to zebra fur stripes. It is believed that British politician James Callaghan was the first to use the term.

Creating these markings is a precise technical process. Workers often use a hand-guided pedestrian cross striping machine to paint the lines. First, the road section must be swept clean and kept completely dry. The painter pulls a guiding line straight and fixes the ends to the ground. They then spray or brush a primer layer onto the asphalt or concrete. Most workers use thermoplastic paint, which is melted into a liquid state before application. The painter then pushes the machine along the guide rod to create the stripes.

Beyond simple markings, urban design includes various ways to manage traffic flow and safety. Pedestrian refuges are uncontrolled crossings that use a central traffic island and dropped kerbs. These islands allow people to cross one direction of traffic at a time. Research suggests that these refuges can decrease pedestrian accidents by approximately 40%. They also help narrow the road, which can slow down vehicles. Some cities also use courtesy crossings, which use colored surfacing to encourage drivers to let people pass. Even in places with formal rules, "guerrilla crosswalks" are sometimes created by groups to demand better safety in neglected areas.