If we reduce traffic on Mill Road, will this increase traffic on other roads, notably Cherry Hinton Road and Coldham’s Lane?
Although traffic displacement is used as an argument against low-traffic neighbourhoods, getting actual figures is rather hard. It’s been remarkably little studied. (If you find any figures, please let us know!)
Walthamstow (right at the tip of north London) is one of the only comprehensive studies so far. Its results are interesting. A mixed residential and business area had traffic restrictions placed on it which resulted in halving the vehicles on these roads. But the traffic on the surrounding main roads went up. That’s bad news, and shows that displacement is a real thing. However, it’s not that bad: the traffic increased by around 11%. Even with this increase, the traffic of the whole area decreased. But it’s hard luck on those residents living on the streets with increased traffic.
While figures for Mill Road, Coldham’s Lane and Cherry Hinton Roads are incomplete, data so far suggest that restricting traffic on Mill Road doesn’t substantially increase traffic elsewhere. You can read more about this on our article about displaced traffic on our resources page.
However, residents from Petersfield going to the big Sainsbury’s did have a roundabout route during the bus gate restrictions. Romsey tradesmen wanting to get to Travis Perkins had to go via Screwfix. A longer journey is more pollution, and more congestion on congested roads.
There’s no easy answer to this. (There is to the Travis Perkins problem as TP’s Devonshire days are numbered!) Coldham’s Lane in particular is a thorny problem because, unlike Mill Road, whose shops existed before cars, the shops on Coldham’s Lane are designed to be driven to.
The biggest problem is perhaps the lack of information. We need to find out where people are travelling from and where they’re going before we can make sure that Coldham’s Land doesn’t get Mill Road’s rejects.