Across most of the developed world, a fair proportion of speed limit-related law enforcement has moved from human hands to the realm of machines. But where a human traffic policeman might give you the benefit of the doubt if you don't slow down quickly enough when the limit falls on a road, a camera will merely record that you overstepped the mark, and that's it. So a good knowledge of speed limits and where the automated systems enforcing them are located is essential for the modern driver. This is where TomTom's Speed Cameras comes in; it's pretty much all the app does.
TomTom's Speed Cameras is an app for iOS only, like the company's fully featured sat-nav app. It's even more restrictive, though, because a mobile data connection is a necessity. So it only runs on the iPhone 3GS and above or one of the 3G iPads. It's not compatible with the iPod Touch or wifi-only iPads. The app itself is free, but it's entirely useless on its own. You will need to purchase a subscription, which costs £16.99 a year, although an introductory offer of one month for £1.49 is available.
With the app installed and a subscription applied, the interface couldn't be simpler. During regular driving, a stylised road graphic fills the screen, with a speed limit sign on the right and your current speed on the left. If you're within the limit, the speed shows in white, but if you exceed the limit it changes to light red then a darker red. We noticed that Speed Cameras wasn't aware of the limit in some suburban side streets, except where this had been reduced to 20mph. However it should be fairly obvious the default speed is 30mph in residential neighbourhoods, and all major roads were detected correctly.
The main function of the app, of course, comes into play when you are approaching a speed camera. This can be a fixed camera, a mobile camera, a traffic light camera, or an average speed camera, although you can also turn any of these off independently. As you near the camera, a warning beeps and a distance countdown begins at the bottom. There's also an icon to show you which type of camera to look out for. Occasionally, cameras are detected that are not on your current route, but just around a nearby turning, which is a particularly handy safeguard if you turn into a side street that also involves a reduction in speed limit.
An even more useful feature is the way average speed zones are presented. Instead of just telling you to keep below the limit, Speed Cameras keeps track of your current average within the zone. So if you do end up accidentally going too fast at any point, you can peg your speed back enough to keep the average legal. For very long average zones, this will be very handy indeed.