The Federal Motor Carrier Safety Administration and the Pipeline and Hazardous Materials Safety Administration are set to publish a joint final rule Wednesday in the Federal Register regarding the transportation of hazardous materials as part of an effort to reduce crashes at railroad crossings.

It prohibits drivers transporting certain hazardous materials from entering onto a highway–rail grade crossing unless there is sufficient space to drive completely through the grade crossing without stopping. There are more than 21, 000 such crossings in the U.S.

This action comes nearly 20-years after Congress passed the Hazardous Materials Transportation Authorization Act of 1994, and was amended last year in the nation’s highway funding authorization.

Both agencies published a notice of proposed rulemaking in January 2011.

FMCSA and PHMSA say they expect 2.62 fewer crashes per year, when all states adopt rules compatible with this Federal rule and 0.3 fewer train derailments. Both estimate the total annual benefits from crashes avoided to be approximately $946,000, consisting of $473,000 in reduced injuries, $1,800 in reduced hazardous material spills, $33,000 in reduced highway property damage, and $438,000 in reduced costs for train derailments.

The American Trucking Associations along with a public safety organization and other groups, asked both FMCSA and PHMSA to require states and local jurisdictions to post signs at the nation’s grade crossing that did not have ample distances, but both agencies said they do not have such jurisdiction.

The new regulation takes effect 30 days after publication.