[单项选择] Traffic statistics paint a gloomy picture. To help solve their traffic woes, some rapidly growing U.S. cities have simply built more roads. But traffic experts say building more roads is a quick-fix solution that will not alleviate the traffic problem in the long run. Soaring land costs, increasing concern over social and environmental disruptions caused by road-building, and the likelihood that more roads can only lead to more cars and traffic are powerful factors bearing down on a 1950s-style constructions program. The goal of smart-highway technology is to make traffic systems work at optimum efficiency by treating the road and the vehicles traveling on them as an integral transportation system. Proponents of this advanced technology say electronic detection systems, closed-circuit television radio communication, ramp metering, variable message signing, and other smart-highway technology can now be used at a reasonable cost to improve communication between drives and the peop
A. car pooling must be studied
B. overall strategies must be coordinated
C. rapid mass-transit systems must be introduced
D. flexible work hours must be experimented