Lisbon is connected by rail and road to the interior of Portugal and to the rest of Europe. The 1.5-mile- (2.4-km-) long 25th of April Bridge, one of the longest suspension bridges in western Europe, has served as the main roadway into the city since it was built in the mid-1960s.
NHTSA estimates that 73% of light vehicles already voluntarily will have rear-view cameras by the final deadline of 2018 and that the cost per vehicle to equip the remainder will be $132 to $142 for a complete system, $43 to $45 to add the camera to a vehicle that already has an adequate display screen.
The sensor systems might work well as parking aids but they aren't informative enough to tip you to the presence of someone, particularly a small child. Other vehicles have backup cameras incorporated into their ($2,000 to $3,000) navigation system and some appear in the rear-view mirror. When you shift into reverse, the screen shows a wide-angle or fish-eye view to the rear.