New Hampshire will soon build high-speed electric vehicle charging stations along major state roadways.

Officials have put out a request for proposals to construct the charging areas over the next 18 months, with some online by the end of next year.

The state will put up $2 million for the project, drawn from its settlement in the Volkswagen emissions tampering case.

This was highlighted in a July report about electric vehicle (EV) infrastructure, commissioned by the state Department of Business and Economic Affairs.

"Investing the settlement money now will encourage greater EV adoption, enable a superior business case for private investment in EV charging infrastructure, and lead to greater cumulative emission reductions over time," the report states.

Now, the state is seeking proposals for a network of parking areas with high-speed vehicle chargers that may or may not be free to use.

They would feature a mix of two kinds of chargers -- "Level 2" stations that take a few hours or less to fill a car's battery, and "direct current fast charging" or DCFC stations that can take less than 30 minutes.

The federal Department of Energy says DCFC stations are ideal for a quick charge mid-trip.

The slower the charger, the DOE says, the longer a user should be expected to want to park there. Faster chargers also tend to cost more and be compatible with fewer types of vehicles.

The state says these charging areas should connect to around 400 miles of busy highways and routes across the state -- including in the White Mountains, on northern I-93 and Route 2.

"Mountain roads in winter are some of the most challenging trips EVs will take," says the state's July report. "Installing direct current fast charging (DCFC) along these routes and Level 2 charging at destinations such as ski slopes and hotels will keep New Hampshire at the center of winter recreation tourism as the EV market grows."

Electric vehicles made up about 2 percent of new vehicle sales in New Hampshire last year, but the state says that market share will likely grow "as additional models become available, familiarity increases, and charging infrastructure expands."

Proposals for the EV charger corridors are due in January. The state will hold an informational session on the application process on Dec. 6.