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Study finds half of London car crashes take place in 5% of the city’s junctions

The location of road accidents is not random and they tend to be highly concentrated in urban areas, according to a new UCL study. The study, published in the open-access journal PLoS ONE, found that nearly 50% of the serious and fatal accidents in London take place in 5% of road junctions.

The study examined the location of more than 200,000 road accidents which occurred in central London over a ten-year period, and observed that data against 1,000 accidents that took place over a two-year period on motorways connected to Mexico City.

Transport for London figures show that 70% of road accidents occur in central London, and the researchers in this study found that car crashes in central London were highly concentrated to specific locations, such as the area nearby underground stations Camden Town and Elephant and Castle, where a road accident is expected every six weeks, and a person is severely injured or suffers a fatal accident every year. This suggests that the environment, such as poor lighting, road surfaces or road layout, increases the likelihood of car crash.

In contrast, they found that the location of motorway accidents are more dispersed. The statistically random location of motorway accidents suggests that human error or a car malfunction for example, rather than an environmental factor, increases the likelihood of a car crash.

The study used a new metric, the Rare Event Concentration Coefficient, to measure the concentration of road accidents based on mathematical model that was applied to two types of road incident data: urban and motorway environment.

The methodology we use in this study provides the ability to compare between different periods or types of accident to determine the impact of a safety program. Our study can also be adapted and applied to other locations across the UK and globally.

—Professor Steven Bishop (UCL Mathematics)

The research is a collaboration between UCL and the LICIT Laboratory from the Université de Lyon/ENTPE/IFFSTAR. The paper was supported by the Mexican Government via a Conacyt Scholar and the Cimplex project, funded by the European Commission.


  • Prieto Curiel R, González Ramírez H, Bishop SR (2018) “A novel rare event approach to measure the randomness and concentration of road accidents.” PLoS ONE 13(8): e0201890 doi: 10.1371/journal.pone.0201890



This 5% & 50% or (1/10) ratios is similar to the frequent 20% & 80% or (1/4) found in many places and/or industries.

Accident prone corners (junctions) are often related to street design and traffic level. Pumps to slow excessive drivers 100 feet or so before exposed junctions are used in many places with great success. Automatic radar cameras is another effective way.

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