M5 - A417 Comments

The other day (admittedly due to bad weather conditions) the A417 was at a standstill, so having come off the M5 northbound at 11A and trying to get to Cheltenham I thought the best option would be to get back on the motorway and try the next junction up - junction 11. It turns out that this is impossible as there is no way onto M5 northbound and no slip road onto A417 westbound. Why can you not do either? Am I missing something here?

The dual carriageway under construction in the photo [since updated] connects the junction to the Gloucester Business Park. The decision not build a direct northbound access to the M5 here was - as things tend to be in the UK - very shortsighted, as the Business Park is one of the biggest development sites in the south west with many major distribution warehouses established as well as thousands of houses on the way.

Clearly your motorway designer has never tried to drive around the Gloucester ring road from the south in the rush hour. Access Northbound from the West would reduce the traffic flow on the ring road (which is, incidentally, one of the poorest excuses for a bypass of any city in the country. If he's responsible for that too, I'd like to strangle him).

I went through this junction a couple of weeks ago. The reason for the "missing" slip road off the roundabout onto the A417 is because the motorway slip road has already started and there's not enough room to fit it in (without weaving). What does seem to be the biggest problem, which hasn't been touched upon, is there's no northbound motorway access at all to the roundabout junction (and thus the spur to Gloucester Business Park), which seems very strange. Do they only want traffic from Bristol?

As I use it to get to and from London, I would have appreciated a better sliproad from the A417 to the M5 north. It's so tight that it's difficult for traffic to get up enough speed to join the motorway properly.

Why isn't it a full movement junction?

If you look at the wider picture you'll note that the M5 junction 11 is just a few kilometres to the north with a high standard 70mph dual carriageway (the A40) linking the towns of Cheltenham and Gloucester to the M5 (north) i.e. there was little point in providing the west to north movement at junction 11A [the same is true of most other missing movements].

There's never any traffic?

I think the main reason you don't think there's any traffic is because the junction is free flowing and therefore you cannot visualise in fact the traffic volume it is quite high, not M25/M4 junction proportions but all the same quite high.

Why isn't there just a normal roundabout and slip roads?

Good question, in the analysis of the junction layouts we did test the twin bridge layout using a computer programme called Arcady ... And it's a good job that we didn't build a twin bridge junction as during peak hours the queues stretch for miles, honest, no joke but sorry it just doesn't work.

Why is it so big?

Well it's not that big, it's not as big as a fully grade separated junction eg. M25/M23 and not as small as a twin bridge junction, it's in between the two, which is exactly what it is, a partial movements partially fully grade separated junction.