A year after crash tests began in Texas, Lake Pontchartrain Causeway officials said Wednesday that a much-discussed project to improve safety on the twin 24-mile spans could go out for bid in late 2016.

The long-discussed project, which officials hope would sharply reduce the number of “overboard” crashes — those in which a vehicle goes off the bridge into the lake — still has to clear several hurdles before it can become a reality, cautioned Carlton Dufrechou, general manager of the Greater New Orleans Expressway Commission, which operates the Causeway and the Huey P. Long Bridge.

First, officials have to decide exactly what form the project will take. Dufrechou said the commission’s staff considered seven options ranging in construction time from one to four years and in cost from $31 million to $1.8 billion. The most expensive option, to build an additional lane or shoulder along each span, was ruled out as too expensive.

Each of the other options would include putting some form of safety rail on at least the southbound span — the older and more dangerous of the two. All but one of the 14 overboard crashes since 1994 have occurred on the southbound span; most of them resulted in death.

The option favored by the GNOEC staff, Dufrechou said, would install a double steel rail on top of the southbound bridge’s 25-inch-high concrete barrier. In addition, intermittent “safety bays,” 672-foot-long sections of shoulder alongside the roadway, would be added to both spans between the existing crossovers.

That plan would cost approximately $104 million and take two years to build, he said.

The safety bays would give motorists an additional area where they can pull over if their car breaks down, as happens several times per day on average, Dufrechou said. While few of those breakdowns result in accidents, some of the 13 accidents on the Causeway in November involved vehicles that were stranded in one lane of the bridge, he said.

Before the commission can pick a project and move forward, however, it is awaiting the results of two studies: a long-term traffic analysis and a financial study of how to pay for the project. The latter should be ready by the commission’s February meeting, Dufrechou said.

No financial option is off the table, he said, including one that has been hotly debated at times: raising tolls, something that has happened once in the bridge’s nearly 60-year history, when the cost went from $2 to $3. For drivers with a toll tag, it is still $2. The GNOEC also plans to pursue any state or federal funding, but as Dufrechou noted, “the economy is tight.”

After the studies, the GNOEC would have to take any preferred option to the Jefferson and St. Tammany Parish councils for approval to issue bonds. The state Bond Commission would also have to give its approval.

Getting the rail on the southbound span, where the concrete barrier is 6 inches lower than on the northbound bridge, is key, Dufrechou has said.

The older of the two spans was completed in 1956 and was built for the low-slung automobiles of that era. At 25 inches, its concrete barrier is too low to prevent today’s higher vehicles from going over the side; one driver who survived his overboard wreck said the barrier in fact acted like a ramp. The hand railing on top of the concrete barrier does nothing to stop cars from going over.

The proposed steel railing would raise the barrier to 47 inches.

Follow Faimon A. Roberts III on Twitter, @faimon.