A new type of opinion poll using "robo calls" is providing a daily insight into the horse race for Honolulu mayor and a ballot issue on rail.

As of yesterday the results, available at www.touchtonepoll.com, show Mayor Mufi Hannemann holding a 8.7 percentage-point lead over challenger Ann Kobayashi.

Responses also favored the city's rail transit plan by 5.1 percentage points with about one week to go before the vote. Results, which have a margin of error of plus or minus 3.8 percentage points, show the vote on a rail referendum likely to be closer than the race between Hannemann and City Council member Kobayashi.

The results are similar to last week's Honolulu Advertiser/ KGMB9 Hawai'i Poll, which showed Hannemann and rail likely to prevail on Nov. 4.

"I think that there's a very good chance that Mufi's going to win, and it's still up in the air for rail," said Honolulu entrepreneur Richard Halverson, who developed the automated, daily updated poll as a software experiment.

Halverson, president of Honolulu software development firm GuideNet, developed the automated phone poll in partnership with part-time Makaha resident Martin Dunsmuir, founder of Seattle-based voicemail transcription service GotVoice. Their robopoll correlates registered voter lists with listed phone numbers and connects them to an automated phone dialer.

The system plays questions and then records answers that respondents provide by pressing numbers on their telephone keypad. Respondents are asked how they would vote in the mayoral race and on the rail transit ballot question. They're also asked their gender, party affiliation and age.

Each day, the system uses 12 phone lines to dial about 5,000 Honolulu homes between 9 a.m. and 8:30 p.m. A rolling three-day average of the responses is tabulated and posted daily at www.touchtonepoll.com. As of Sunday the system had gathered 5,781 valid responses to the poll since Sept. 24.

The pool of respondents polled by www.touchtonepoll.com excludes registered voters with unlisted phone numbers and cell phone-only users.

Among those dialed by the automated touch-tone poll was Rebecca Ward, president of Hono- lulu polling firm Ward Research Inc. Ward said the wording of the poll's questions was straightforward and that the poll relies on a large sample. However, automated polling faces the same problems that traditional polling companies face, including a difficulty reaching the typically younger segment of the population who use only cell phones.

Traditional polling firms try to overcome that problem by randomly dialing phone numbers, then screening the responses for registered voters, Ward said. Attempts also are made to balance the pool of respondents to prevent the results from being skewed by gender, age or other demographics. Through Sunday, the pool of respondents at www.touchtonepoll.com were weighted towards female and older residents. That could affect the poll's accuracy, because other polls show older voters tend to oppose rail.

Still, "Surveys like this one (by www.touchtonepoll.com) really do come close to matching what we get from screening through the greater population to find registered voters, because it tends to be the most stable parts of the population that show up at the polls," Ward said. "It's another way of doing what we do."

However, "You do lose the interviewer connection, and often when people hear an automated voice they assume it's a sales presentation, and they hang up," Ward added.

Halverson's poll averages about 200 completed responses a day, which is about a 4 percent success rate.

Other issues that can skew robopoll results include an inability to control which household resident responds to the poll, or to prevent nonvoters or unlikely voters from completing the survey, Halverson said. On the other hand, robopolling promises to be a less labor-intensive and lower-cost alternative to traditional human-based polling methods.

Halverson said he started polling in February and has since successfully predicted results in primary elections held in Nevada and Hawai'i.

Ultimately, Halverson hopes to profit from subscription fees and by licensing or selling his Internet-browser-based software to others looking to conduct their own polls. So far, the www.touchtonepoll.com Web site has four paid subscribers that pay a fee to access survey results by district as well as results from House and Senate races, Halverson said.

The future success of the technology could hinge on how successful the Web site can predict November's winners.

"Right now the jury's out," said Halverson, who ran unsuccessfully for the state House in 2004. "After this election, I'll either have a whole bunch of new friends, or this will be just another project that Halverson started that went down the tubes."