40mph Speed Limit Sign, Post Mounted Diagram 670 R2/RA2This 40mph speed limit sign is durable and easy to install onto almost any post or pole. 40mph speed limits are used in many locations especially in rural areas where a faster national speed limit leads to a 30 mph limit. In more built up areas 40mph limits are often seen on dual carriageways leading out through suburbs. For official guidance on speed limit sign positioning, refer to the TSRGD Traffic Signs Manual Chapter 3, page 105 and onwards. We