The High Points and Low Points of the A303

A few miles west of Andover, travellers along the A303 cross from Hampshire into Wiltshire and shortly thereafter encounter Beacon Hill; with Boscome Down and Porton Down visible to the south and Bulford over the crest of the hill to the north.

At the summit of Beacon Hill, at a height of around 560ft above sea level, is perhaps one of the most important points on the entire length of the A303.  Obviously, it's a high point because it is at the highest point of Beacon Hill. But the reason it's a low point is much less obvious.

Can you think what it might be?  Why do we regard it as a low point?  Need a clue?

OK, take a look here then:

Can you see it now?  Look in the foreground to the left of the carriageway.  Can you see how the strip of tarmac immediately to the left of the continuous white line all but disappears?   The similar strip on the right hand side of the carriageway continues for a few metres further, to roughly a point level with the back of the car transporter ahead of the Google Earth camera car.

So what?  We would argue that this point is where the A303 changes from being a high quality trunk road with carriageways wide enough to take modern traffic, to the narrow roads that lead beyond, past Stonehenge, to Winterbourne Stoke.

Apart from a few (but, not all) of the more modern dual carriageway sections and the 3-lane "death trap" sections, that little strip of tarmac never re-appears between the top of Beacon Hill and Penzance.  It never ever appears on an un-dualled section of the A303.   It represents the effective loss of 1.2 metres off the overall width of a single carriageway road, or 2.4 metres off the width of a dual carriageway.  That little strip of land, that inocuous-seeming piece of tarmac at the edge of each lane might represent the difference between life and death for a pedestrian, a cyclist or a motor-cyclist.  That's how important it is!  Life and death important.

According to the Department for Transport in its Design Manual for Roads and Bridges (2005), the specifications for rural dual and single carriageway roads are as shown below (click on the picture to get a larger view).

So East of Beacon Hill, by and large, the A303 complies with this, but West of Beacon Hill, all the way south west through Somerset and into Devon, down to the junction with the A30, it largely doesn't.  The consequences of this are fairly damning - west of Beacon Hill, the A303 is largely not fit for purpose, it certainly isn't fit to be a trunk road.  It isn't really fit to be an un-trunked A-road.  All this assumes that the lanes of the A303 (the bit between the centreline of the carriageway and the outermost edge of the edge line are 3.65 metres in width.   We should never take anything for granted and the width of these lanes is something we will return to later.

I'm sure that someone somewhere will take delight in pointing out that these are modern standards and that you can't expect an old road to match such a standard.   To an extent a fair argument, particularly for a road that had followed its current course for a century or more.  But as we saw in earlier posts, that doesn't really apply to the A303 and the stretch between Amesbury and Mere, through Winterbourne Stoke, in particular.  The A303 only came into being in 1958 - fairly recently in the great scheme of things.

Perhaps the most embarrassing point is that shown in the first photograph.  Someone, somewhere decided to make the A303 metalled surface 2.4 metres narrower to the west of Beacon Hill summit than it was to the east.   Now just which half-wit, or half-wits, were responsible for that piece of forward thinking?  Perhaps it is time to de-trunk the A303!