Between exiting the city centre and the M6 junction 6 ("Spaghetti Junction") at Salford (on the border between Aston and Erdington), the modern route follows the A38(M) Aston Expressway, an unusual 7-lane, single carriageway (and speed limited to 50 mph) urban motorway which uses an electronic signage-controlled tidal flow system to provide 3 lanes each way off-peak, and a 4/2 lane split at peak times (prioritising citybound traffic in the morning, and outbound traffic at night). This merges directly onto the M6 in both directions, as well as the A5127 and A38 surface streets, via an intertwined series of flyovers, meaning there is an uninterrupted run from the motorway and these suburban feeder roads all the way to the southern ring road junction. The original route is now taken by the A5127, starting and terminating at the same points but providing a somewhat slower ride through mixed industrial and residential areas with several roundabout and traffic light controlled at-grade crossings, and since signed and re-engineered with a focus on local access, public transport and non-motorway traffic.