Shippers and truck brokers sued over their alleged negligent hiring of a trucker involved in a serious or fatal accident would need only show the carrier held proper federal operating authority and met minimum insurance requirements to likely prevail in court, according to critics of a Senate bill passed last week reauthorizing federal transport spending for the next six years.

The provision, contained in legislation approved by the Senate Commerce Committee, makes it significantly easier for shippers and brokers to insulate themselves from the legal consequences of failing to vet a carrier's safety record before hiring the carrier, highway-safety advocates said today in a conference call with reporters. Henry Jasny, vice president of Advocates for Highway and Auto Safety, an advocacy group, said the bill requires shippers and brokers to meet just the bare-minimum standards for carrier hiring and still successfully defend themselves in court if they are sued for damages after the carrier was in an accident.

Personal-injury lawyers have brought a number of successful cases in state courts against brokers on grounds that they were negligent in reviewing a carrier's safety history before hiring them to move a shipper's load. Plaintiffs' attorneys have also persuaded juries that carriers were in the brokers' employ at the time of an accident.

Brokers have maintained that they only engage truckers on a transactional basis, that drivers are not on brokers' payrolls, and that they do a thorough job of vetting a carrier's safety fitness beforehand. The Transportation Intermediaries Association (TIA), the lead broker trade group, has lobbied Congress for a nationwide hiring standard for carriers that would set specific criteria for choosing a safe motor carrier. Robert A. Voltmann, TIA's president and CEO, was unavailable to comment.

The alleged broker-friendly language was just one item on a laundry list of concerns voiced by safety advocates over the bill, the "Comprehensive Transportation and Consumer Protection Act of 2015." The bill was approved last Wednesday by a 13-11 margin, with no Democrat voting for its passage. It will be consolidated with legislation passed by the Senate Environment and Public Works Committee to form the Senate's version of what has been commonly known as the "Highway Bill." The consolidated bill is expected to reach the Senate floor as early as this week.

Sens. Richard Blumenthal (D-Conn.) and Edward Markey (D-Mass.), appearing on the conference call, said they would pull out all the stops to prevent passage of a bill they said is anti-safety. "This is a devastating missed opportunity" to reduce accidents and deaths on the road, Blumenthal said during the call.

Sen. Dianne Feinstein (D-Calif.), is expected to introduce an amendment to prevent the rollout of 33-foot twin trailers on all federal-aid highways until the Department of Transportation conducts a study on their safety. The current federal limit is 28 feet per trailer, though 18 states allow the larger equipment on their portions of federal-aid roads. Supporters of the provision, which has been included in House and Senate versions of the Department of Transportation's fiscal year 2016 appropriations, said the longer trailers come with equally long wheelbases that improve stability and performance. They added that the longer trailers would enable shippers to load more cargo into the same number of vehicles, thus cutting the number of trips by the thousands. Safety groups said the nation's highways, in particular merge lanes and on-off ramps, were not designed or built to accommodate tractor-trailers 10 feet longer than the current threshold.

Advocates for Highway and Auto Safety attacked a provision to remove from public view the carrier safety scores developed under the Federal Motor Carrier Safety Administration's "Compliance, Safety, and Accountability" program, better known as CSA. The scores would not be made public until the Transportation Research Board, required under the Commerce Committee's bill to study the controversial CSA program, publishes its report, and recommendations from a corrective action plan have been implemented. The American Trucking Associations (ATA) has long urged FMCSA to withdraw the carrier grades, saying the methodology doesn't effectively identify high-risk carriers and relies on a limited amount of data. Safety groups said the measure shields unsafe carriers from necessary public scrutiny.

Safety advocates also said they would oppose language in the bill that would authorize the DOT secretary to launch a six-year pilot program to allow states to enter into reciprocal agreements authorizing licensed truck drivers between 18 and 21 to operate on interstate highways. Under current law, drivers cannot operate a commercial motor vehicle in interstate commerce until they turn 21. However, licensed drivers between 18 and 21 can operate within the borders of the states where they are licensed.

Jackie Gillan, head of the group, said accident rates in states that allow 19- and 20-year-old drivers to operate in intrastate commerce are 4 to 6 times higher than in states that don't. Gillan said lawmakers should be working toward limiting the ability of drivers under the age of 21 to operate heavy-duty trucks, not expanding their opportunities. Trucking interests that face a worsening driver shortage said it is absurd that a driver can, for example, operate 500 miles within California but not be allowed to drive 50 miles to and from any of the states that border it.

The Senate is racing to beat a deadline of July 31, when the most recent extension of federal transport-funding authorization is set to expire. The House voted last week to extend the program until the end of the year so it could work on a long-term plan to fund it. The Senate has yet to vote on an extension. The White House has said it will support an extension until the end of the year, but sources in Washington said President Obama has no intention of going beyond that.

Federal projects are financed through excise taxes on diesel fuel and gasoline. The proceeds are deposited in a trust fund that disburses the money. Those taxes have not been raised since 1993, and federal spending on transportation has been falling in inflation-adjusted terms as vehicle-miles traveled have declined and more fuel-efficient vehicles require fewer fill-ups at gas stations.