Neither new regulations nor opposition from the taxi industry seem able to slow down the ride-hailing business in Hawaii. Lyft, which entered the Oahu market in 2014, just joined competitor Uber on Maui, Kauai and Hawaii island, signs that both companies are bullish on the future. A Honolulu ordinance requires taxis and ride-hailing companies to register with the city, certify their drivers and maintain records. But rather than crimp their app-based operations, it’s made them easier to expand, said Robert Deluze, owner of Roberts Taxi. “The playing field is so uneven, it’s unbelievable,” he said. Some business trends may just be unstoppable.