Forum Topic

Saturday tailback on A316

At about 18:20 on Saturday evenings there is a tailback on A316 from Chiswick bridge to Hogarth roundabout. By 19:30 the road is clear.  Where are they all going?

Christopher Shea ● 21d9 Comments

I would disagree that it is clear cut. Since Covid, the passenger numbers at Heathrow have risen back to record levels  bringing a corresponding rise to vehicle movements on the A4. That must have had an effect on traffic light phasing which has increased northbound queues on the A316. That is not to say that the LTN isn't adding to the tailbacks but rather we don't know until either proper traffic study is done, or, as you suggest, it is shut down for a week or so to evaluate the impact.

Jeremy Parkinson ● 11d

I live on the A316 just south of the Hogarth Roundabout. Northbound queues on the roundabout were rare before the LTN came into force and have been near-constant from the day of its introduction. This is as clearcut a cause and effect phenomenon as it is possible to get. If you want to try to validate it by removing the LTN, then please go ahead.

Adrian Haberberg ● 13d

How do you know this? The main reason for northbound delays on the A316 is the priority, quite rightly, given to vehicle movement on the A4. I think I have observed an increase in queueing back from the Hogarth Roundabout since the LTN was introduced as have other people who live in the area but it is hard to say with complete certainty that his is down to traffic being barred from Grove Park.

Jeremy Parkinson ● 14d

Yes the Grove Park LTN causes huge problems for northbound traffic.

Steve Taylor ● 17d

Although it is likely that the Grove Park LTN lengthens the northbound queues up to Hogarth Roundabout I don't think it affects southbound traffic. It is possible to cut through Grove Park to head towards Chiswick Bridge at any time by using Hartington Road.

Jeremy Parkinson ● 17d

As suggested, it could be that the traffic lights on the Hogarth roundabout give precedence to 'rush hour' traffic leaving town until around 19.30, when it gives more time to 'ground level' A316 traffic.There's also the intentional ban on through traffic sullying the avenues of Grove Park and having to use the roundabout, which doesn't apply after 19.00.

Peter Evans ● 18d

That's very interesting. This is a complete guess but perhaps the phasing is set to clear traffic from Hogarth Roundabout going west and south as quickly as possible in the evening rush. This released traffic hits a bottleneck on the A316. The quick evaporation of traffic doesn't occur during the week because there are more vehicles on the road but only becomes apparent on Saturdays. Just a theory.

Jeremy Parkinson ● 18d

Yes every Saturday.

Christopher Shea ● 20d

Is this every Saturday? If so, it probably has something to do with traffic light phasings rather than a specific event.

Jeremy Parkinson ● 20d