Some residents are raising new concerns about Segways on crowded Waikiki sidewalks, saying the increasingly popular motorized scooters go too fast and are too large to mingle safely with busy pedestrian traffic.

"Bikes are not allowed on sidewalks in Waikiki, but Segways are. It's a real problem," said Walt Flood, member of the Waikiki Neighborhood Board, which will take up the Segway issue at its next meeting on May 13.

Flood and other board members say they have heard about Segways injuring pedestrians or frightening them, because the scooters are quiet and can come up behind people without them noticing. Flood said he wants Segways banned from Waikiki sidewalks, or their speeds reduced.

But Segway users and rental operators say there are already plenty of safety precautions in place to make sure pedestrians and Segway operators can co-exist on sidewalks. The law says the Segways cannot go over 8 mph on sidewalks, but many Segways go slower in Waikiki, they say. (Under standard settings, Segways are capable of speeds up to 12 mph.)

They also say they have not seen any serious injuries involving Segways.

And the only authorized dealer of Segways on O'ahu says he doesn't allow people to buy the machines, which run about $5,000 to $6,000, before they have passed a training class and feel comfortable on the scooters.

"The Segways in many different ways are safer than the (motorized) wheelchairs we allow to be used on sidewalks," said Alan Rice, owner of Segway of Hawaii, which opened in 2006 at the Hilton Hawaiian Village.

There's no telling how many Segways are on Waikiki sidewalks every day, but the number likely isn't very high. Rice, the only tour operator who specializes in Segway jaunts in Waikiki, said his company takes at most 30 people out per day, and that includes his other tours, too, of Ala Moana and Diamond Head. All his tours start at the Hilton Hawaiian Village.

Rice estimates there are about 100 privately owned Segways in Hawai'i. The rest are used for tours or by companies or agencies, including the Honolulu Police Department, which uses Segways in Chinatown and Downtown.

The Segway was introduced in 2001.

Hawai'i is one of 42 states that allow Segways on sidewalks and bike paths. The 2003 Hawai'i law on Segways also says riders must be at least 16.

In addition to sidewalks, many states also allow Segways on roads.

Eight states have not passed any legislation on Segways, but several do have county-level rules that apply to the scooters, according to the Governors Highway Safety Association. Meanwhile, some cities have passed bans or tightened restrictions on Segways on sidewalks, including San Francisco.

But Segway tours have become more popular in a host of tourist destinations, including Waikiki, as an eco-friendly way to see a city.

City Councilman Charles Djou, who represents Waikiki, said he has received complaints about Segways on busy sidewalks on Kalakaua or Kuhio avenues, and sees why the scooters would present a problem.

Waikiki has the busiest sidewalks in the state, he said.

"Generally speaking, the problem with Segways is in Waikiki," he said.

But Djou said there is not much the city can do.

The state law on Segways would have to be changed for a provision regarding Segways on Waikiki sidewalks to be added, he said. And with the legislative session almost over, Segway opponents will have to wait until next year before they can petition state lawmakers to revisit the Segway law.

Rick Egged, president of the Waikiki Improvement Association, said he will be taking up the Segway issue with businesses this month to see whether the concerns go beyond residents. "I do have some concerns about safety issues," he said. "But we haven't formulated a position yet."

Egged said the issue presents "no easy solution."

Bob Finley, chairman of the Waikiki Neighborhood Board, agreed, but said he is interested in hearing from Segway operators at upcoming meetings, especially if the safety concerns can be hammered out without a change to the law.

He said Waikiki sidewalks are uniquely busy. Not only are there thousands of tourists walking daily, there are street performers at night.

Flood, of the neighborhood board, said he has almost been hit by a Segway because it came up behind him so quickly. He said at least the scooters should be given horns so they can alert pedestrians.

Rice, the Segway tour operator and dealer, said he is open to any suggestions residents have and wants to meet with them. He said Segways look faster than they actually are. Most Segways traveling in Waikiki, he said, go 3 to 4 mph — the speed of someone jogging. And, he added, he doesn't take anyone on a tour of Waikiki unless he feels like they are ready.

Rice said his Segway tours of Waikiki and elsewhere usually have between four to six people.

The only other Segway tour operator on O'ahu, called Segventure, advertises trips from Ala Moana to Downtown.

Dan Carr, who uses a Segway for his own transportation and for work with Diagnostic Laboratories at The Queen's Medical Center, said Segway opponents don't know how easy the scooters are to handle.

If they did, he said, they would have no concerns with them on sidewalks.

"A Segway is like an extension of yourself," he said.

Carr added that recently, when his family visited O'ahu, he took them on a Segway tour of Waikiki. Though the sidewalks were busy, he said, it was easy to maneuver around people and keep a distance from pedestrians because Segways keep riders up high with a wide field of vision.

"It's a marvelous piece of technology," he said.