WASHINGTON -- The U.S. Department of Transportation wants to toughen its workplace drug-testing program for bus and truck drivers and other transportation workers, including testing for the drugs ecstasy and heroin.

The department has published a proposed rule that also would lower cutoff levels for cocaine and amphetamines and authorize employers to use test facilities certified by the U.S. Department of Health and Human Services to conduct initial drug testing.

HHS has estimated there may be 10 percent more users of amphetamine and cocaine identified using the lowered cutoffs.

Jim Swart, director of DOTs Office of Drug and Alcohol Policy and Compliance, said in a statement that the proposed rule is intended to more closely align much of the USDOT program of direct-observation urine drug-testing with stringent HHS drug-testing guidelines.

The USDOT will take comments on the proposed rule until April 5.

The drug-testing proposal has been on USDOT rule-making agenda for nearly six years, when HHS revised some of its mandatory workforce drug-testing guidelines for federal agencies.

"In this rule, we are seeking to harmonize our proposals for laboratories, collectors, medical review officers and employers with the new requirements contained in the revised HHS mandatory guidelines," the proposed rule said.

Annette Sandberg, a transportation consultant and former administrator of the Federal Motor Carrier Safety Administration said during a conference call last month that she didnt expect the new drug-testing standards to be implemented soon.

She said USDOT is busy with more urgent trucking issues, such as a revised hours-of-service rule for truckers and electronic onboard recorders.

The USDOT said it does not believe the tougher standards will be costly or burdensome from a record-keeping standpoint because of the relatively low incidence data.

Comments on the proposal must include the docket number, OST-2010-0026 or RIN 2105-AD95 for identification and may be submitted by the following means:

Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the online instructions for submitting comments.

Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Ave. SE, West Building Ground Floor Room W12-140, Washington, D.C. 20590-0001.

The Federal Register notice may be read in full at http://edocket.access.gpo.gov/2010/2010-2315.htm.