|Location Map ( geo)|
|The Interchange from the Air|
|Modified Fork/Roundabout Interchange Hybrid|
|M90, A90, A85|
Barnhill Junction the second northern most motorway junction in the British Isles, is junction 11 of the M90 and formerly junction 1 of the M85. Whilst it may look rather confusing, at its heart is a deformed roundabout, and despite the M90 sliproads entering the roundabout from the middle it does provide full movement between all routes. Lets take a tour round the junction to prove it!
From Perth, the A85 splits with eastbound traffic getting priority onto the 'roundabout' over the small amount of circulating traffic. A couple of full access (when taking into account the one-way controls of the 'roundabout') side turns provide access to properties, the right turn being the old line of the A85 as it headed towards Dundee. The A85 is now signed with the lefthand lane for Dundee and the righthand for Perth. A single lane then drops down from the M90 and takes priority over the Perth lane of the A85, whilst the A90 lane continues unhindered, with a white hatched zone separating the two lanes. In theory no traffic should be using the 'roundabout' to go from the M90 to A90, as the route continues over the flyover.
Taking the Perth bound lane then, after giving way to traffic leaving the M90, the 'roundabout' turns around under the M90-A90 mainline and is quickly joined by westbound traffic leaving the A90, heading for Perth. The two main lanes then diverge, with the lefthand lane becoming the A85 into Perth, whilst the righthand lane climbs to join the M90. Whilst there should again be no traffic making the A90 to M90 manouvere through the 'roundabout', this option is not directly prohibited as it is for eastbound traffic.
Continuing round the 'roundabout', a left turn leads into the small settlement of Walnut Grove, strung along the old line of the A85, and this brings the road back up to two lanes after a brief section that was hatched down to one lane. This is now the final section, passing under the Friarton Bridge, and heading into Perth as the A85. Just before the road drops back to a standard S2, the right lane splits, allowing traffic to double back around the 'roundabout', as noted at the start of our tour. The two mainline westbound lanes merge into a single lane.
|Edinburgh, Stirling, Glasgow, Crianlarich, Inverness|
|Aberdeen, Dundee, Forfar|
|Perth, Coupar Angus, Blairgowrie, Braemar|
|West Kinfauns, Walnut Grove, The Holdings|
|Edinburgh, Stirling, Glasgow, Crianlarich, Inverness (M90)|