The federal, Ontario and Quebec governments have launched a study to decide whether to build a new bridge, tunnel or ferry crossing connecting Ottawa and Gatineau.

The National Capital Commission announced Tuesday that six public consultations will take place in the two cities in June as the first step in an environmental assessment expected to take four years and cost $4 million.

The study by consultants ROCHE-NCE will look at how badly a new crossing is needed, what type of crossing it could be and where it could be located.

The federal, Ontario and Quebec governments are funding the study, while the cities of Ottawa and Gatineau will offer technical support, the NCC said in a news release.

NCC spokesman Chris Gordon said interprovincial crossing studies have been conducted in the past, but never with this level of co-operation between the parties.

"It's not starting completely fresh in that we certainly are not completely discounting all the information that was collected and thought up in the past," he said. "We'll use that as background information for us as an input into our data collection."

There are currently five main bridges connecting the two cities.

Ottawa Coun. Alex Cullen said there has been talk of a new bridge for years, but now the region's growing population and traffic have increased the chance that a new crossing will actually be built.

Public consultations scheduled between June 6 and June 18 in various occasions will mainly seek input about the study's process, its terms of reference, and the preliminary crossing types and locations.

More public consultations will be held further along in the process, the NCC says.

The NCC is a federal agency that manages federal lands and buildings in the Ottawa-Gatineau area.