Difference between Britain's speed limit and the United States?

Answer 1

The speed limit in the UK and the US is indicated in miles per hour.

There are no de-restricted public roads in the UK and the maximum speed limit in force is 70 mph (this excludes private property and motor racing circuits).

Speed limits in the UK are indicated on circular signs with a red border. They are written in black text on a white background.

The Lancashire Partnership for Road Safety (see related link) gives the following guidance on speed limits:

• 20mph speed limit - used mainly in town centres, high streets, residential roads and near schools.
• 30mph speed limit - used mainly in urban areas and villages and wherever you see street lights unless otherwise stated.
• 40mph and 50mph limit - mainly used in non-built up areas and where the national speed limit is not appropriate.
• National speed limit - For most vehicles the national speed limit is 60mph on single carriageway roads and 70mph on dual carriageways and Motorways.

Guidance on the speed limits for differing vehicles (i.e. coaches and HGVs or vehicles towing trailers) is given in the Highway Code (available online, see related links).

In the US the speed limits are set by the differing states so are variable. According to Wikipedia, the lowest maximum speed limit is 55 mph in Hawaii and the highest is 80 mph speed limit on certain rural roads in Texas. See related link.

The US FHWA (Federal Highways Administration) is currently developing a tool to help decide what speed limits are appropriate for differing roads and the surrounding environment. This may be useful in understanding how speed limits are chosen. See related link.


In the US:

Each state has its own standards for speed limits. Because of that, wide variation of the speed limits exists, even from city to city (as sometimes cities are left to set their own rules as well).

Generally speaking however...

25 MPH is generally what the posted limit is in narrow residential streets, or near schools. These zones are also sometimes set to lower numbers. Depending on what's nearby (deaf children, a hospital loading zone, etc) the limits can go down to 5 MPH.

35 is the limit on most residential streets.

55 is common among interstate highways within city limits.

65 is common among interstate highways in suburban areas.

75 is common among interstate highways in rural districts, with some having no limits posted or enforced at all.