MAKIKI, Hawaii -- For the first time, the state has begun looking at installing traffic roundabouts to improve traffic safety at intersections, as an alternative to stop lights and stop signs.

The city started building traffic roundabouts on Oahu city roads nine years ago. But only now has the state written up an official policy on roundabouts for state highways.

The city has several traffic circles and roundabouts on Oahu, like this one in Makiki on Keeaumoku Street just mauka of Wilder.

Research has shown they reduce fatal accidents by 90 percent and can also effectively slow traffic through neighborhoods.

The state recently installed its first roundabout in Kapaa on Kauai.

"The feedback that we get from motorists on Kauai, they love it, it's working out really well and they've adjusted really positively to it," said Brennon Morioka.

In December, the state issued its first formal policy on roundabouts, saying they should be considered as alternatives to stop lights and stop signs.

"It does need to be built at the right location, at the right time and for the right reasons. We're not just going to go throw a roundabout because it sounds like a nifty idea," Morioka said.

For years, Kahaluu community activist John Reppun said he has asked for a roundabout where Kahekili and Kamehameha Highways merge in Kahaluu near the Hygienic Store.

"They do force people to slow down and they are so easy to negotiate," Reppun said.

The state said it's planning new left turn lanes and longer merging lanes here, but rejected a roundabout in Kahaluu.

"If we were to stick in a roundabout at that location we probably would have to condemn the hygienic store, and I don't think the people of Kahaluu would really want that," Morioka said.

"I hope they will see the light with Kahaluu. But whether it's Kahaluu or somewhere else in the state that begins for us all to do this ... It's a good step," Reppun said.

The state wants to plan roundabouts where it will not have to condemn homes and businesses.

"We're looking at some of the more rural areas where you have a lot less development right now, where putting them in now won't really affect too many of the homeowners," Morioka said.

Morioka said the state is considering putting in traffic roundabouts on the Big Island, in Ka'u, Puna and Keeau.

He said the state will take proposals for roundabouts to communities first to hear their concerns before beginning any project.