A study released Tuesday by The Road Information Program says about 25 percent of the nation's major bridges have structural problems or are obsolete. The transportation research group says the nation needs to spend $3.6 billion more annually to upgrade the bridges.
TRIP says structurally deficient bridges have problems such as crumbling decks, supports or other major components. Obsolete bridges often have narrow lanes or are misaligned with roads that approach them, creating hazards.
Oklahoma led all states with the largest number of deficient bridges at 33 percent. Missouri (26 percent), Rhode Island and Pennsylvania (25 percent), and South Dakota (23 percent) ranked among the bottom five. Several heavily traveled bridges in larger cities, including New York, Boston, Detroit and St. Louis, have significant deficiencies.
The study found truck traffic is expected to skyrocket 90 percent by 2020, to 256 billion miles traveled from 135 billion in 2000. Overall, vehicle traffic is expected to jump 50 percent from 2.7 trillion miles driven in 2000 to 4.1 trillion miles in 2020.