In the ever-evolving battle between the trucking and railroad industries, an unlikely third party is playing a rather important role. State Troopers, who are lobbying in Washington this month for their own interests, are also lobbying in support of the railroad industry.

According to the New York Times, Congress is now preparing to take up renewal of the Highway Trust Fund, which runs out of money at the end of next month. The fund finances billions of dollars that are allocated for road construction, the repair of bridges, and other improvements to the country’s infrastructure.

The amount of government funds aren’t typically enough to cover the need for infrastructure and roadway repair, which is essential for transportation and shipping.

The National Troopers Coalition seeks to keep larger and longer trucks off of the roads in the U.S., because they are more likely to cause fatal accidents. Coincidentally, the railroad industry stands to benefit from legislation keeping bigger trucks off of roads.

Truckload shipping and railroad shipping are often chosen over shipping by air, since fuel prices are less expensive, which can reduce freight prices and lower parcel costs for retailers. However, according to researchers at Texas AandM University’s Texas Transportation Institute, lost work hours due to traffic delays cost the U.S. economy $121 billion in 2011 alone and wasted almost three billion gallons of gasoline. More trucks on the road won’t help.

The trucking industry is hoping to add language to the legislation that permits larger and longer trucks, but the railroad industry is poised for just the opposite.

Both methods of transportation contribute to the transportation industry’s 28% portion of the overall carbon dioxide emissions in the U.S., but that issue isn’t even really on the table in this debate — green initiatives aren’t the point here.

The trucking industry argues that if there are larger and longer trucks on the road, there will be fewer of them. The railroad industry says that larger trucks and truckload shipping do more damage to roadways.

It’s hard to guess which industry will come out on top in this battle, but we’ll know by May 31st — which is when the Highway Trust Fund runs out of money.