The A898 is probably one of Britain's shortest primary routes. At only 2 miles, it is not long but very useful as it makes a shortcut to the West Highlands allowing traffic to get to/from the M8 without passing through Glasgow.
The A898 starts at J1 of the M898. Before March 2006 and the abolition of tolls, traffic would have to stop here to pay the toll, which explains why all the slip roads are on the same side of the dumbbell. Now, drivers can continue directly over the cable-stayed Erskine Bridge, opened in 1971. The bridge itself offers views of the airport, Erskine, Dumbarton and the Kilpatrick Hills.
After the bridge, we approach the only other junction on the A898, a directional T with the A82. Traffic heading for Loch Lomond, Crianlarich and Fort William takes the left lane northbound, and Clydebank and Glasgow-based traffic takes the right lane. Although the A878 from the centre of Old Kilpatrick also ties into the Old Kilpatrick Interchange it is inaccessible from the A898.
The A898 number seems to have been allocated specifically to the Erskine Bridge, together with the similar M898 just to the south. Prior to the opening of the bridge, traffic crossed the Clyde via the Erskine Ferry just upstream, which was part of the A726. That road, however, ended on the A814 meaning that all traffic had to go through the centre of Old Kilpatrick to reach the A82.
Although the Erskine Bridge didn't open until 1971, no earlier use of the number has yet been found, leaving a curious gap between the A897 and A899.