Saturday, 7 May 2011

Along the Fosse Way: mapping a new road


The A46 between Widmerpool and Farndon (near Newark) is being reconstructed as a dual carriageway and is due to open next year.

Kev Swindells has done a great job mapping the southern section of these road works to the junction with the A6097 at East Bridgford. Several sections are already in use, and once again OpenStreetMap is more up-to-date than other online maps. The most obvious of these is the big new roundabout West of Bingham (below, also compare with Google Maps).



At our first pub meetup in Nottingham I asked Kev he was going to do any mapping North of East Bridgford, but apparently its beyond his normal bike runs. I'd already taken some audio notes last summer and had marked in a new overbridge near Elston. So on a nice spring evening I decided to see how much information I could collect for the remaining part of the route. I tried to cross the line of the road works on as many minor roads as I could, starting from Newark and working my way back towards East Bridgford.

IMG_3569a

Even with decent waypoints for the crossings it's not straightforward to get the rest of the alignment. Several things do help:
  • Powerlines. Lots of powerlines cross the Trent S of Farndon, and all have been mapped (from surveys, Bing and OS OpenData). From photos I can check how the road alignment compares to pylon positions.
  • Field Boundaries. Most field boundaries visible on Bing are still there: obviously they've gone along the construction zone, but again it's useful information.
  • Hedgerow Trees. The farmland on the E side of the Fosse Way towards the River Devon has little in the way of trees and no patches of woodland. Each large tree which can be located on a photo can be matched to the Bing imagery.
  • Aerial Photography. In a couple of places the Bing imagery is recent enough to be able to see that the ground has been cleared in preparation for construction. This was particularly useful just N of Flintham close to the point when the new road crosses the old road (nothing on the ground yet: presumably this will be the last phase of construction.
This mapping is very preliminary: Kev mapped the Southern section in multiple visits by noting where the roadworks obstructed cycleroutes. Ideally more of the local minor roads and footpaths could be mapped to add to the detail as the road nears completion. This is particularly true near East Bridgford. The precise location of the two carriageways is also not clear: round RAF Syerston it looks as if the cutting is not completely excavated yet.

All Saints Syerston : 3581aAll Saints Hawton : 3535a

I didn't forget to collect other data: the little village of Syerston was missing all its roads. It has a nice little church too. I was able to do a bit of general tidying up of the other minor roads. Another nice church, which was already mapped is at Hawton: this has a very fine Easter Sepulchre in the chancel. Both churches are dedicated to All Saints.

5 comments:

  1. Really nice piece of detective surveying. I have enjoyed this kind of work myself, especially before decent aerial imagery. The Bus stops on the map above look a bit stranded though. :)

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  2. I hope Kev reads this: it's his patch :-)

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  3. Excellent. A whole load of the old A46 is due to become National Cycle Route 48 (Fosse 2), I believe...

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  4. Just come across this - at 20:00 Thursday the Highways Agency were supposed to have moved the traffic onto the new North Bound carriageway somewhere north of Margidunum (A6097) and just north of RAF Syerson - the Newark Beer Festival being on the following day gave me a nice excuse to map the new alignment.

    Just 36 hours after this supposed switch the change was already going into OpenStreetMap, complete with the Fosseway Flyer's route - apart from the bit in Nottingham City centre - (very convoluted near RAF Syerson it has to be said, involving the bus doing a three point turn) - my phones GPS managing to get the Northbound and Southbound traces overlapping most of the way from Margidunum to the Farndon (really surprised me how similar they were).

    If anyone is up that way I'm not too sure about the bit from between leaving the old A46 about 1km north of Margidunum and Lodge Lane - the traces make it look like the southbound carriageway was used for a bit before switching to the north bound one. The weird looking bit just north of Syrerson is correct though - the Highway's Agency website says the access road is used round there (it was noticeably narrower here) - Looks like this is where they need to merge the East Stoke bypass into the online widening. The bus stops also need some work - it appears a new stop has been added in Syrerson and I assume this will replace one of them on the Fosse Way.

    I wonder if the county council's pledge of £20 million will be enough to kick off the A453 widening (and therefore NCR 15 between EMA and Clifton) to give us a few more years of OSM being more up to date than anything else round here? (I'll not hold my breath though, that had has been on the cards since the 1960s). Alas the commercial providers have caught up with the realigned A612 so we won't have three new ones at once.

    As for the Bus Stops at the Bingham roundabout - I'll check them out next time I'm that way!

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  5. Good stuff: I was there after 8:00 pm on Thursday but they had only closed the side roads, the realignment onto the new carriageway didn't happen until sometime early on Friday morning. You've saved me another trip.

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