M4 motorway not signed, European route E30 includes most of the M4. The M4 has two sections of smart motorway. The one between junctions 19 (M32) and 20 (M5) north of Bristol has variable speed limits and a part-time hard-shoulder. Completion was in summer 2014. The section between junctions 24 and 29 in Newport has variable speed limits. In 2010 it was announced that a smart motorway would be constructed between junctions 3 and 12, with work starting in Autumn 2018. This will be the longest smart motorway scheme in the United Kingdom, with a length of 51km (32 miles). Work is
Bushmaster M4-type Carbine federal law which states a minimum barrel for a rifle. There is also a military M4 Type Carbine which comes with a barrel and a removable "bird cage" flash suppressor. An M4 Type Post-Ban Carbine was developed for the 1994 United States Federal Assault Weapons Ban requirements. Since the ban expired in 2004, this rifle has essentially been replaced by the M4A2 and M4A3. Some states in the U.S. have kept these laws, so the rifle is still being produced. A trademark dispute between Bushmaster and Colt concerned the use of the "M4" name. The M4 was developed and produced