Traffic in the US drives on the right and distance and speed are measured in miles. Fuel, known as "Gas", is delivered in gallons and is generally cheaper than other western countries. It is common to pay for fuel before filling your tank. Whilst speed limits vary between states, Freeways in the West operate up to 75mph (121kph) whilst Eastern States are 70mph (113kph). Some states operate minimum speed limits on their freeways and turnpikes.