Hornshill Junction

Hornshill Junction is junction 3 of the M80. It was originally built in 1992, consisting of a tight pair of forks off an unbuilt mainline with a short spur to the B757 to the north and a longer spur to Crowwood Roundabout to the south. It was rebuilt into a roundabout junction upon opening of the M80 in 2011, with both spurs (and the A8006) being partially rebuilt to form the A806.

The junction today is a fairly ordinary 4-way motorway roundabout sitting above the M80 mainline. However, owing to the history of the site, the two arms of the A806 are both skewed round to the west, to meet the roundabout, the southern arm particularly so as it leaves the roundabout almost parallel to the new motorway line, before twisting round south, following the former curve of the M80 to reach Crowwood Roundabout on the A80.

History

For many years, this half-built junction had a single bridge (the current western bridge of the roundabout), which only spanned the eastbound carriageway, the tarmac for the proposed westbound mainline running out just east of the bridge. The eastbound carriageway then turned south to meet the current line of the A806 approximately where the road straightens up. The westbound route actually followed the line of the A806 up to the roundabout (which hadn't yet been built of course) and then had a right hand lane gain from the B757 spur which had crossed the bridge, before dropping down the current slip road to rejoin the mainline of the M80.

Routes

Route	To	Notes
M80	Glasgow
M80	Stirling, Kincardine Br
A806	Kirkintilloch
A806	Stepps
B757	Achinloch, Lenzie
A8006	Kirkintilloch