Transportation Secretary Elizabeth Hanford Dole has made a number of speeches extolling transportation safety, and is kicking around the idea of creating a new empire to merge several safety functions scattered throughout the department.

If it happens, it will be called the Surface Transportation Safety Administration. The STSA would include all the present programs of the National Highway Traffic Safety Administration, plus some safety functions of the Federal Highway Administration, the Research and Special Programs Administration and the Urban Mass Transportation Administration.

The new subagency presumably would end some of the more interesting differences of opinion that have been expressed at DOT over the years. Particularly on matters of trucking safety, NHTSA, which sets standards, and the FHWA's Bureau of Motor Carrier Safety, which enforces them, have disagreed over what was "in the public interest."

The bureau would be merged into the STSA, a move that some feel would end that bureau's long history as a bothersome stepchild in an agency devoted primarily to pouring concrete.

From RSPA would come the responsibility for writing regulations on transporting hazardous materials, while enforcement of that function among truckers would come from the bureau. The Federal Aviation Administration and the Federal Railroad Administration still would enforce hazardous-materials rules and other safety rules in their areas.

The STSA would also pick up the RSPA's job of regulating pipeline safety and the UMTA's responsibility for setting transit bus safety standards.

The STSA would require congressional approval. At least two similar proposals are circulating on Capitol Hill. THE "A" TEAM . . . Dole appointees are now in place in almost all the important sub-Cabinet positions, although several still have to surmount the cumbersome FBI clearance process before the White House formally nominates them.

Just this week the White House finally nominated Diane K. Steed to be NHTSA administrator, a position she has held in fact if not in title since Raymond A. Peck Jr. resigned in response to underwhelming support from the secretary's office.

James H. Burnley IV, Dole's general counsel and the most influential and trusted of her advisers, is expected to become deputy secretary shortly, although his replacement as general counsel has not been decided yet. Ralph Stanley, who has been acting as Dole's chief of staff, is expected to be nominated as UMTA administrator to replace the departed Arthur Teele.

Mari Maseng, who was a White House speechwriter, has been named assistant secretary for public affairs. CONRAIL UPDATE . . . One of the priority issues for Dole is the proposed sale of Conrail, the northeastern freight railroad that ate up more than $3 billion in federal subsidies before it turned a profit last year. The only formal offer on the table is from Conrail employes, acting through the Railway Labor Executives Association.

That offer includes $500 million in cash, which the employes would borrow and then repay from the railroad's profits. That would make it, in effect, a lien against the railroad, a prospect that does not please federal officials. They want to be sure that Conrail never again becomes a ward of the government.

Santa Fe Industries, which owns the profitable Atchison, Topeka & Santa Fe Railroad, has expressed interest, and its officials are now busily poring over the Conrail books. If Santa Fe buys Conrail, the first coast-to-coast railroad could be in the offing. Even more interesting is the fact that Norfolk Southern Corp., another railroad holding company, owns 5 percent of Santa Fe Industries.