The A77 is a major trunk road in Scotland. It links the city of Glasgow in the central belt, linking the towns of Kilmarnock, Prestwick, Ayr, Maybole, and Girvan on a south westerly route to the town of Stranraer in the south west, passing through the counties of Renfrewshire, Ayrshire, and Wigtownshire.
It then continues for a further 8 miles west as a non-trunk road , terminating in the holiday town of Portpatrick on the Rhinns of Galloway coast. At its northern end, it is a motorway-standard road (the M77) between Newton Mearns and Central Glasgow.
The A77 is important as it acts as both the main link to Prestwick Airport, and it also serves the three main ferry terminals for sailings to Northern Ireland - namely Stranraer, Cairnryan, and Troon, and as a result carries a lot of commuter, tourist and heavy goods vehicle traffic.
Despite numerous upgrades, (Ayr and Kilmarnock were bypassed in the 1970s, while the motorway sections were created in the 1990s), the Northern Ayrshire stretches of the road suffer from gross undercapacity. The most notorious section, an unsegregated 4-lane single carriageway between Kilmarnock and Newton Mearns is one of the most dangerous and accident-prone sections of road in Scotland, owing to the fact that cars pass each other at over 80mph, despite numerous warnings to drivers that the road only has a speed capacity of 60mph.
In 2003, the long awaited announcement was made that the road would be upgraded to motorway section to Fenwick, where the "proper" dual carriageway section currently begins. This scheme also includes a new "Southern Orbital" road for Glasgow, which will join the new section of the M77 to East Kilbride, therefore bypassing the inadequate and dangerous B764 Eaglesham Moor road which is used by heavy vehicles as a shortcut, but prone to accidents during bad weather conditions.