If looking on google maps it seems like soi 101 is the only way to access khao tao in hua hin by car or bike? Is that correct or there is another road?

Someone in hua hin can confirm this?

Not the only way, but the easiest, depending what part of that area you wish to be at. Depends if coming from the N or the S.

If you coming from the south, Soi 105 is better.