Not to get too bogged down in the transportation of Hawaii, but given that the cost of importing gasoline is likely to be higher for the island ITTL, I wonder if the streetcar system in Honolulu 1) was built and 2) was able to stay viable. Maybe a lot more scooters and bikes, too. I get nervous just thinking about Honolulu traffic and it would be nice to think TTL is spared from the most incongruous aspect of "paradise."
There are also the remnants of several mostly agricultural rail lines around the islands. While some were done in by unavoidable natural disasters, I wonder if others might've fared better ITTL.
Honolulu has no rapid transit system other than buses. There was never the capital investment (nor internal desire) to form a streetcar system in the nation's capital. Over in the former city of Brentford, the British had ample capital and ample desire to have a means of rapidly transporting their soldiers & sailors around the city (notice how PCM's Red Line goes into Old Town, which could be used by officers coming off of Cook Island, or to transfer marines to Cook Island to be loaded onto ships.) The entire network is designed to funnel men from the city (Red Line, Barnes St and Pohuli) to Haloa Station, which would provide them easy access to the Naval Base. Keaka Station is fairly new, built in the 1980s, which extended the city's reach to Queen's University.
In general, scooters and bikes are more commons across Hawai'i due to prohibitive costs of petrol importation. Those who live in Pu'uola are more likely to own a car. As for the agricultural rail lines, most are still in operation. The lack of trucks and motorised hauling results in a heavier reliance on rail. Most of them are run by British firms. Despite not being in the Commonwealth or a Crown Colony, Hawai'i in inexorably linked to the United Kingdom.