TECHNOLOGY: Study shows that vehicle-to-vehicle navigation systems really do work. “Traffic congestion is not only annoying, it’s expensive. In 2005, traffic congestion cost an estimated $78.2 billion in 437 urban areas in the US, according to the Texas Transportation Institute’s 2007 Urban Mobility Report. The cost is measured by the travel time index, which is the ratio of travel time in rush hours to travel time at quiet periods, and has increased from 1.09 in 1982 to 1.26 in 2005. In addition to the use of public transportation and bicycle commuting to address this problem, some researchers have been developing intelligent transportation systems in which vehicles use near-real-time traffic data to choose the fastest route and decrease congestion throughout the network.”