It was upgraded and extended during the 1920s to serve as a western bypass of Detroit.

The designated A1 later moved to the western bypass around the city, and roads between the two found themselves back in Zone 1.

Which would obviously be a necessary change to make if it was going to relieve the western bypass.

The southern portion serves as a western bypass for the city of Jackson.

Finally in 2005, the M50 was extended to link up to the M11, providing a full western bypass of the capital.

Previously, this 7.5m-wide road acted as a western bypass carrying some 6,500 vehicles per day.

It is the main western bypass of Brisbane city.

The section which serves as the city's western bypass is to be completed some time in 2014.

It will be extended westward to the western bypass, making for a semi-loop around the city.

It is often used as a western bypass for travellers wishing to avoid the city.