If you have a hunch that truck traffic in the region is increasing by leaps and bounds, this is not your imagination.

Because of the proliferation of warehouse distribution centers, particularly in the Lehigh Valley, area motorists are increasingly jockeying with huge tractor-trailers for a share of heavily traveled interstates 81, 80 and 78.But this is only the beginning. A study released earlier this year indicated that truck traffic on interstates and feeder roads such as routes 309, 209 and 22 will likely double by 2040.Not only that, but there is a bill in Congress to allow bigger trucks on our highways. U.S. Sen. Bob Casey, D-Pa., is opposed to the legislation, saying that this "would put the safety of our nation's roads into reverse."Motor vehicle crashes in most area counties were up sharply last year compared to 2011; the lone exception was in Carbon County, where the number of accidents dropped slightly.In nearby Lehigh County, however, crashes were up 45 percent, while Schuylkill had a 25 percent increase and Northampton's rate rose 19 percent.According to the U.S. Census, Carbon County has the third highest percentage of commuters of any county in the state, with 55.5 percent driving to work outside of the county, so Carbon residents encounter increased traffic to and from work in nearby counties.Under the Casey-opposed bill, states would be required to allow what are called "twin 33s," or double-trailers, each 33 feet in length. Only 11 states allow them now, Casey said."I believe bigger trucks on the road means the potential for more accidents and increased danger for children and families," Casey added.Casey pointed to Pennsylvania's terrain, bad winter weather and many structurally deficient bridges as reasons why the bigger trucks would be a bad idea.He cited a U.S. Department of Transportation study which estimated that longer trucks would cause more than $1 billion in damage to roads and $1.1 billion to bridges.Pennsylvania allows double-trailers with a maximum length of 28 feet, 6 inches for each trailer. Single trailers pulled by truck tractors can be 53 feet long.A growing reliance on online shopping will bring an estimated 40 percent increase in double-trailers to congested highways in the next 10 years, according to Ed Patru, spokesman for the Coalition for Efficient and Responsible Trucking.A generation ago, warehouse and distribution centers in the Lehigh Valley area took up about 12 million square feet of distribution and warehouse space; today, it is more than three times that amount - 40 million square feet - with the arrival of amazon.com, Nestle, Walmart, Target and scores more.With the expectation for next-day delivery of goods by online consumers to grow dramatically in coming years, there are numerous major warehousing and distribution projects in the process of being completed or on the drawing board.The FedEx Ground project alone is expected to add 3 million square feet in East Allen Township in Northampton County. This one project is expected to add 1,800 trucks a day to local roads.Bringing goods to market and to consumers in a timely manner requires a robust trucking industry, but the question is how does this need mesh with the safety requirements of the traveling public?Planners have sounded the alarm and are pleading with state, county and municipal officials to take concerted and immediate steps to plan for this unprecedented increase in truck traffic.Not only must it be done, but it must be done on a regional level, because trucks do not stop at municipal and county lines. We are all in this together.BRUCE FRASSINELLI | tneditor@tnonline