|Location Map ( geo)
|Cumbernauld Village (NS769766)
|8 miles (12.9 km)
|A803, B8080, A803, M80, M80, A8011
|Route outline (key)
It starts at a mini-roundabout on the A803 (former A9) to the west of Falkirk town centre, and heads south on Glenfuir Road, running alongside the Forth & Clyde Canal. The two routes climb together - the canal via locks, the road with a gentle gradient to meet the B8080 at a mini-roundabout shortly before road and canal start to diverge. Another mini roundabout provides a bridge over the canal and a short distance further on the road TOTSOs right onto Tamfourhill Road.
The road continues west, skirting the suburb of Tamfourhill, with a roundabout providing access to the Falkirk Wheel, before zigzagging across the Glasgow to Falkirk railway line at a narrow bridge controlled by traffic lights. Leaving the town behind, the road continues westwards through the woods and across fields to High Bonnybridge where it again TOTSOs right. Curiously, the 1932 Ten-Mile Map shows the past mile or so running much further south, perhaps using Lochgreen Road, although there are no obvious connecting roads still in existence that it could have followed on the line shown, suggesting this is an error.
Heading north now, road sweeps steeply down round a double bend to cross the railway line again, although this time the road goes underneath. This bridge is also narrow, with traffic lights installed in recent years. Dropping down past the church, a gated drive to the right seems to be the old road line, but this must pre-date the railways. A short distance along Broomhill Road, the Cumbernauld to Falkirk line is also crossed and this remains a give way. The road then reaches Bonnybridge, passing a mixture of houses and industrial sites. It then crosses a drawbridge over the Forth & Clyde Canal before bending to the right and dropping down to reach a roundabout on the A803 in the town centre.
The mainline of the B816 actually turned off just before the canal bridge, however. The road continues west, once again alongside the canal, and roughly on the line of the Antonine Wall, as far as the next lock, where it diverges a little as the road climbs up with the Roman Wall to the M80 at J6A. The junction is limited access, with north facing slips only, accessed either side of the overbridge. For a time this junction was unusual amongst motorway junctions for having a bus gate on the northbound onslip, but this seems to have been removed. The road then goes under the Castlecary railway viaduct (no giving way this time) before running through Castlecary parallel to the motorway. Parts of the large Ward Park Industrial Estate then sit on the north side of the road, followed by a retail park. The B816 ends shortly afterwards at the next motorway junction, J6, where all movements are allowed. The road ahead is the A8011.
When first classified in 1922, the B816 was much shorter than it is now, simply linking the A80 northeast of Cumbernauld (now J6A of the M80) to the A803 at Bonnybridge (along what is now the spur). This section is still part of the B816, but the route has been extended at both ends, south alongside the motorway along the former A80 into Cumbernauld and east along a partly new-build road into Falkirk. The original route to the A9 in Falkirk was across the canal bridge and along Union Road to end further west on Main Street.