Cities count the number of cars on the road in order to plan everything from the timing of stoplights to road repairs. But the in-road metal detectors that do the counting can make errors -- most often by registering that a car is present when one isn&#39;t. <P>&nbsp;</P> <P>기사원문보기&nbsp;: <A href=&quot;http://www.sciencedaily.com/releases/2012/08/120807132031.htm?utm_source=feedburner&amp;utm_medium=email&amp;utm_campaign=Feed%3A+sciencedaily%2Fmatter_energy%2Ftransportation_science+%28ScienceDaily%3A+Matter+%26+Energy+News+--+Transportation+Science%29&quot;>http://www.sciencedaily.com/releases/2012/08/120807132031.htm?utm_source=feedburner&amp;utm_medium=email&amp;utm_campaign=Feed%3A+sciencedaily%2Fmatter_energy%2Ftransportation_science+%28ScienceDaily%3A+Matter+%26+Energy+News+--+Transportation+Science%29</A></P>