US uses technology to triage nation's potholed roads

Phoenix, Arizona

THE white Ford van rumbled down Devonshire Street, past the green-trunked palo verde trees and gravelled lawns of central Phoenix. Lasers up front mapped the road's roughness, and high-definition cameras on spider-like arms in the back recorded continuous images of cracked asphalt.

With 65 per cent of US roads rated in less than good condition, cities and states no longer leave funding decisions to intuition and influence. Instead, they use data vacuumed up by arachnid-armed "spider vans" with bulbous cameras and global-positioning equipment protruding from roofs. Six computers inside Phoenix's four-tonne vehicle stored data for engineers to download.

"Our roads are in pretty tough shape," said Mark Glock, the city's deputy street transportation director. "Our annual budget is US$23 million. We are on a 65-year cycle and we know pavement only lasts 35 years. We're very l…