The only thing more frustrating than creeping your way toward the site of a bottleneck on the highway only to discover the accident is on the other side of the median are the times when you make it through and discover, as far as you can tell, nothing was holding up the traffic. Japanese researchers have now demonstrated that the "nothing" may in fact be the traffic crossing a threshold of density of cars on the road. Too many cars means that small slow downs by a few drivers equals up to big backups miles away.

Municipalities are always weighing cost against environmental concerns and quite often, cost wins out at great expense to the environment. Residents of New York City will remember the summer of 2002 when the Bloomberg administration ceased recycling glass and plastic, citing budgetary concerns. It was cheaper for the city to dump tons of reusable refuse into landfills than to continue its recycling program. After a year of no plastic recycling and two years of no glass, the city determined the savings were negligible and resumed recycling both.