A3 - A243 - A309
You are here: Home - Bad Junctions - A3-A243-A309
Ordnance Survey map - Alternative aerial view
Where is it?
South of Kingston, where the A3 Kingston Bypass becomes the A3 Esher Bypass.
It was spotted by Dave Ryan.
What's wrong with it?
For a start, the roundabout interchange with the A243 only has two lanes each way through the underpass - it's the narrowest point on the Kingston Bypass. The lane is dropped too early - the A309 takes a large amount of traffic but all of it has to squeeze under the roundabout first.
But that's not all. The A243 is a major road into Kingston and you can only reach it... southbound, when you're pretty much past Kingston. Northbound traffic either has to come off too early and go through Esher or too late at Tolworth. Of course, that doesn't stop some people: you can always exit northbound by pulling across the merging sliproad from the A243 and diving off down a residential street. Stupid? It wouldn't be necessary if the junction worked.
And still there is more. The underpass itself is not properly drained. It doesn't just form puddles when it rains, it forms the kind of lake that makes drivers of small cars come to a sudden stop half way down the slope, causing major delays in bad weather.
Why is it wrong?
The access problems can be explained quite easily. The Kingston bypass was built in the 1930s and originally returned to the A3 line by what is now the A309 here. In the 1970s, the Esher bypass was constructed, branching off the Kingston bypass at this point. Historically there had never been access to what is now the A309 from the west so it wasn't provided when the Esher bypass was built. The rest can only be explained by a lack of foresight in the engineering of the interchange.
What would be better?
The land actually exists to built south-facing sliproads from the A309, and free-flowing ones at that! But back in the real world, perhaps the drainage problems can be sorted out.
Right to Reply
Email me with your comments.
Tim suggests an alternative:
I know this junction well - one of the problems it causes is that as there is no access to the A3 westbound from the A243 all traffic from the area trying to reach the A3 has to join at Tolworth (the next junction east), which makes that junction overloaded, and squeezes more trafic through the two-lane section. And, of course, traffic leaving the A3 cannot do so until Tolworth.
I don't see access from the Esher bypass to the A309 as the priority - a more direct route to Esher is to leave the A3 at the previous junction (A244). Traffic into southern Kingston is more likely to benefit from provision of access to the A243. A solution would be to change the sense of the slip roads between the A3 and A309, so that instead of linking the A309 with the underpass, they link the Esher bypass with the roundabout. Yes, A309 traffic would then have to use the roundabout, but the much larger flows to and from the A243 could be accomodated.
Andy Kyriakides thinks it's OK:
Oddly enough the roundabout section works quite well, no traffic lights needed to stagger it out. It's only the A309 entrance which is bad. Approaching it from the A3 or either side of the A243 is ok, apart from small side road which appear half way up the slip road (common for this part of the A3!) and have cars darting out on the main road as if they didn't care about if they were alive tomorrow. The worst part is the merging of the A309 into the northbound A3. You actually have 5 lanes of traffic merging into 2 - the A3 northbound is virtually motorway standard before this junction, but just before it you have 3 lanes of national speed limit traffic squeeze into 2 lanes of 50mph traffic with a speed camera to boot! Add to this 2 lanes of traffic from the A309 forced into this to go into a very thin 2 lane underpass and you can imagine how messy it can get. Add the drainage issues to this and it becomes a nightmare! But overall it still works and flows better than its neighbour, the A3/A240 junction at Tolworth, which often has knock on effects onto the A3 itself.
Matthew Smith disagrees with the prosecution:
The A309 is not a major route into Kingston. The A309 is part of the original Kingston By-Pass (and is still called Kingston By-Pass Road), and was used by traffic bypassing Kingston on the way to Esher, Guildford and Portsmouth. There are four good roads approaching Kingston from London, points east and Leatherhead.
Today, traffic going south now leaves the KBP at Hook West, with the A3 running along the new Esher By-Pass, which finishes at the junction of the A245 at Cobham and is of near-motorway standard. The old KBP, however, is still used by people getting from London to Esher, and from other points east (Sutton, Wimbledon, even Croydon) to Esher, Staines, Hampton Court, Walton and the M3. It's effectively across south London to Staines and the M3.
I agree that the Hook underpass is really too narrow, since going eastbound it takes all the traffic from Portsmouth and Esher, that is, five lanes of traffic, into two lanes. Although I've never encountered the sort of congestion you might expect.
John Gardner thinks more sliproads are a good idea:
Living myself to the north west of this junction, I would certainly appreciate south-east facing sliproads from the A309 onto the A3. This would enable me to bypass Esher en route to the M25 etc, Esher being a busy town these days. South west-facing slip roads from the A243 roundabout onto the A3 too make good sense, not least to improve the options available to traffic to get into Surbiton/Kingston from the south or out of the Chessington area headed south/south west. On the face of it there seems to be land aplenty to accommodate both extra options and this would also facilitate a 'meaningful' lane drop, from the A3 northbound carriageway.
With thanks to Dave Ryan for information on this page.
