The legal speed limit for driving within the town of Slough is 20mph for all vehicular traffic. Along single carriageway motorways, such as the A4 and A412, the speed limit increases to 60mph, but along dual carriage motorways, such as the M4, M25, M40 and A355, you are allowed a maximum speed of 70mph. Expect visible and hidden red light and speed cameras near all primary junction points and observe good driving etiquette as you go. Search rental cars on KAYAK