The first country ever to set a speed limit was the UK, back in 1865. The limit was set at 10 mph, but someone then decided that was far too reckless a speed limit and reduced it to 4 mph in rural areas and to 2 mph in towns. One Mr Waltor Arnold thought he was above the law and being something of a daredevil was caught driving at the astonishing speed of 8 mph on January 28th 1896, making him the first person ever to get a speeding ticket. Speed limits have been raised somewhat over the years, but they are by no means universal, with different countries (and sometimes different administrative regions within countries) setting different speed limits throughout their territories. Here are some speed limits for cars to keep in mind on your travels.
The UK and the USA are virtually the only two countries in the world where speed limits are set in mph. Everywhere else, speed limits are set in km/h. Both car displays and signs in those countries show speeds accordingly.
'Vias reservadas' refers to roads, such as the former SCUTs, where the only vehicles allowed are cars and motorcycles. Some national roads cross through towns or villages, where you'll often come across speed-sensitive traffic lights, so be sure to slow down.
There's a widely held belief that German Autobahns have no speed limits. However, while that is largely true, there are exceptions. Some Autobahn sections do have speed limits (some permanent, some dynamic), ranging from 80 to 130 km/h, so always keep an eye out for those.
There are plans to change the speed limit in motorways to 80 mph in 2013, making it the first change to speed limits in Britain since 1965. However, for the moment, the limit remains set at 70 mph.
Speed limits in the USA vary greatly from state to state, and sometimes within the same state between counties. Speed limits can go from 60 mph in Hawaii to 80 mph in parts of Texas. However, the most common speed limits are 70 mph in eastern states and 75 mph in western states. Some parts of the USA also enforce minimum speed limits. Also, in some places, there are different speed limits for daytime driving and for nighttime driving. It's also worth noting that despite speed limits, the legislation in most countries dictates that despite official limits in a given road, the speed should be adequate to the general conditions of the road (subject to traffic, weather, etc.)