|Length:||20.5 miles (33 km)|
|Meets:||A4095, A40, B4449, A420, A338, A34, B4017, A4183, B4015, A4074|
|Former Number(s):||B4022, A34|
|Old route now:||A4074, A4130, A404|
|Route outline (key)|
The A415 is one of the losers in the ever-changing number-swap that is Oxfordshire's road system. It originally ran from the A420 at Kingston Bagpuize to the A4 near Maidenhead, providing a useful back route across the Chilterns avoiding the larger bottlenecks of Oxford and Reading. In its journey it crossed the Thames no less than three times, taking 40 miles to do what the river does in 80. Nowadays most traffic prefers the faster delights of the A34 and M4, or the M40 and A404, but the old road still has its enthusiasts, despite the attempts of OCC to hide it by renumbering. Apart from Abingdon and Henley (the latter certainly worth avoiding during the regatta) it is very quiet, and largely on its original route. However, little of it now retains its original number.
Witney – Berinsfield
What is left is all non-primary. The road starts in Witney, at a junction with the A4095. Originally the A40 passed through the town, but it now crosses the A415 to the south of the town at one of only two GSJs on the route. Ducklington has the A415's only bypass, and the road then follows the River Windrush to its confluence with the Thames at Newbridge. (The 13th-century bridge here is “new” only by comparison with Radcot Bridge a few miles upstream). Both rivers are crossed by humpbacked bridges controlled by traffic lights.
We next cross the A420 Oxford to Swindon (and Bristol) road at the wonderfully named Kingston Bagpuize using a roundabout, and the A338 from Oxford to Wantage (and Bournemouth) using traffic lights. The latter junction is staggered by a few hundred yards. Just before Abingdon is reached, we meet the A34 at a GSJ. Given the narrow streets, hump backed bridges and everything else we have encountered, it is not surprising that heavy traffic is signposted from here to Witney by the A40 – a sign that should be familiar since it is illustrated in the Highway Code.
We go through the streets of Abingdon (where there was once a multiplex along the A34 between what is now the B4017 and A4183), the one way system being the nearest thing we get to a dual carriageway on this road, and over Abingdon Bridge. We have travelled just six miles from Newbridge. The river, winding its way through Oxford, has taken twenty six, describing a complete 360 degree turn on the way. At Abingdon, the river is actually flowing westwards, but it loops round to the east again just beyond the bridge and we follow it closely now through Culham (Atomic Energy Research Establishment on the left), Clifton Hampden and Burcot to Berinsfield.
This is where the A415 now ends, nowhere in particular, but when the numbers were first given out the A415 continued alongside the river to Benson, in a multiplex with the A42 (Oxford to Reading). In 1935 this part of the A42 was renumbered the A423, and for reasons which shall become apparent the A415 was then truncated to end here. The A423 has in turn lost out to the A4074.
Former section: Shillingford – Maidenhead Thicket
After Dorchester-on-Thames, now bypassed, the A42/A415 multiplex reached Shillingford, which used to be the crossing of the A329. Now Shillingford and Wallingford are both bypassed, and the A329 and A4074 multiplex where once the A42 and A415 did. So at different times this stretch has carried, in multiplex, the numbers A42, A329, A415, A423, and A4074.
At Shillingford the A42 and A415 roads parted company again, the former A42 (now A4074) heading for Reading whilst the A415 (later the A423) headed over the Chilterns to Henley. However, RAF Benson has obliterated part of the old A415 (Benson was bypassed in the 1930s and the runway severed this as well as the old road!), and traffic now remains on the A4074 to Crowmarsh Gifford. Here the A4074 (successor to the A42) and A329 continue south, the latter to cross the Thames by its newest road bridge, the Winterbrook Bridge. This also carries the A4130, originally just Didcot to Wallingford but now also the new identity of the next stage of the former A415.
From here the road was renumbered first as an extension of the A423, but that in turn has had its day and it is now the A4130. The river now swings south through Reading, but the road which was once the A423, but is now the A4130, heads up the hill to rejoin the original A415 route, up and over the southern Chilterns, through Nettlebed, to Henley. Through Henley the A415 was subordinate to the A32, but as that road is now the non-primary A4155, the A4130, being primary, takes precedence
At Henley we leave Oxfordshire for Berkshire (although until 1974 the Newbridge to Abingdon section was also in Berks) as we cross the Thames for the last time, and climb steeply to run above the Thames valley before dropping to Hurley and then, as the Thames takes a wide loop north through Marlow and Cookham over the hills to Burchetts Green and the A404. The last stage of the original A415 to the A4 junction on the outskirts of Maidenhead is now an unclassified road, having been superseded by the A404(M) – which was once the A423(M).
As stated above, the end points of the A415 have moved somewhat over the years. In 1922 the western end of the A415 was on the A420 in Kingston Bagpuize. It was extended west (or, more accurately, north) to Witney and the A4095 (and possibly the A40) in the early 1930s.
The full length of the A415, from Witney to Maidenhead, only lasted a couple of years. In the renumberings of 1935 the A42 was destroyed. Its route from Oxford to Shillingford was taken over by the A423, which also took over that part of the A415 east of the former A42. This left the 20 or so miles that remain.