|Location Map ( geo)
|North Orbital Road
|Leavesden Green (TQ097997)
|Park Street (TL143050)
|4.8 miles (7.7 km)
|A41, A412, M1, M25, B4630, A414, A5183
|Old route now:
|A412, M25, A414
|Route outline (key)
Starting at a grade-separated roundabout junction on the A41 Watford bypass, the A405 heads north-east then north to bypass Abbots Langley. Although the road is D2 speed is limited to 40 mph owing to the large number of side roads and occasional roundabouts. The limit increases to 50 mph before we reach the M1 at the Waterdale Interchange (Junction 6).
Now carrying traffic between central London via the M1 and the M25, the road passes to the west of Bricket Wood and soon reaches a roundabout at J21A of the M25. On the far side of the motorway – and still D2 – the road bears right at the next roundabout to bypass Chiswell Green and presently we reach Park Street Roundabout to the south of St Albans where we meet the former A5 (now A5183) and former M10 (now A414). The road ends here.
The A405 was originally planned to be part of an orbital road encircling all of London. The North Orbital Road was to be from the Colnbrook Bypass on A4 to Tilbury.
When first built in 1932 or 1933 it ran from the A41 Watford Bypass to the A555 (now A1) Barnet Bypass, west of Hatfield and passing to the south of St Albans. Contractor for the Chiswell Green to Barnet Bypass section was Sir Robert McAlpine and Sons, tender price £302,836.
In 1976 the road was extended westwards to bypass Rickmansworth and meet the A412 at Maple Cross.
The Rickmansworth bypass was upgraded and incorporated into the M25 in 1985 as the section between J17 and the spur at J19 (although the spur at J17 is now the A412). Later still, the St Albans bypass was incorporated into a rerouted A414, giving the road its current length.