Sat nav algorithms to stop directing cars down residential ‘rat run’ streets, TomTom announces
Major navigation firms to rewrite routing algorithms to stop traffic being diverted through small residential streets
Sat nav shortcuts which divert traffic down minor residential streets could vanish under new plans by major navigation companies.
Sat nav giant TomTom said it planned to rewrite its algorithms to stop the creation of rat runs through quiet neighbourhoods. Other major navigation providers including Google and Waze are expected to follow suit in a bid to divert traffic away from small back roads and back onto main routes.
TomTom’s vice president, Ralf-Peter Schaefer, told the Sunday Times that the changes were the results of discussions at the European Commission around reducing noise and pollution in residential areas. The changes are expected to come into effect in the UK in 2025 and 2026.
In-car sat nav systems first appeared around 30 years ago and have long been blamed for routing traffic through smaller streets as shortcuts or to avoid congestion on major roads. They have also been blamed for sending HGVs and other large vehicles down unsuitable routes, causing congestion and road blocks.
Despite their issues, they are now so ubiquitous that navigating using a sat nav has been included in most practical driving tests since 2017.
The AA said the surge in online shopping and drivers’ use of phone-based navigation had encouraged more drivers to use residential streets as rat runs to avoid major roads. AA president Edmund King said changes to how navigation systems plot their routes would ensure that through traffic is “not pushed into the most sensitive areas.”
He added: “We don’t see this as Nimby [not in my back yard] regulation as many of these small roads are not suitable for diverted traffic in safety, environmental or even aesthetic terms.”
Stephen Edwards, chief executive of the charity Living Streets, told the Sunday Times: “people have become so used to traffic being funnelled down their streets by sat navs, and felt powerless to do anything about it, that changes to the algorithm are very welcome”.
Recent data from TomTom showed that urban congestion has climbed back to pre-pandemic levels and revealed that London was the worst city in the world in its 2022 Traffic Index.
According to its analysis, the average Londoner spent 325 commuting during peak hours last year, with 139 hours of that due to traffic congestion. While Dubliners lost more time to jams overall - 145 hours - London was rated worse due to the time taken to travel relatively short distances. The data showed it took an average of 36 minutes and 20 seconds to travel just six miles, with London’s “slow, complex and winding inner-city roads” blamed.
The index also showed that in 21 of the 25 UK cities studied traffic congestion got worse between 2021 and 2022, with drivers spending between 99 and 325 hours in rush-hour traffic. and four UK cities in the global top 50 worst locations for delays.