Townhead Interchange is the notorious Junction 15 on the M8, and for many people as they head west on their holidays to the Scottish Highlands, it is their first experience of sliproads arriving/departing in the centre of the motorway. The junction primarily links the M8 with the A803, although things are further complicated by the presence of the A804 joining the A803 immediately to the north of the junction (at least one sliproad uses the A804 to reach the A803). And, immediately to the south, the A803 terminates on the A8 outside Glasgow Royal Infirmary.
The junction was designed as a freeflowing GSJ, allowing for the eastern arm of the Glasgow Inner Ring Road. This explains the offside slips, as they were intended to be the motorways mainline, the 'through' M8 would have been a TOTSO in effect. However, as this ring road was never completed, the sliproads still retain their temporary destinations on the A803, which subsequently ends at traffic-light controlled junctions on the A8.