The route to the north of the city is also very busy: it runs as a single carriageway up to the junction with the A4174 ring road at Filton, and where it runs as Gloucester Road is a busy shopping parade. Beyond the ring road, it runs as a dual carriageway past Filton Airport which lies in South Gloucestershire, which contains bases for Royal Mail, Airbus, Rolls Royce and others. Beyond the junction with M5 it runs as a broad single carriageway, again parallel to the M5 in route towards Gloucester.