Driving on Malaysian Roads

Hello/Hai/Salaams all. Going on our 2nd holiday to Malaysia in less than two years, that's how much we loved it! 🇲🇾🫶🏻❤️‍🔥

This time, planning a self-drive. Some advice and tips will be appreciated. Will be moving from KL to a few other towns.

1. Do tolls accept cash?
2. This may sound silly, but I've never used a self-service at a gas station. How does this work?
3. Safe to drive at night between towns?
4. Is it necessary to have a car in Penang Island? Or Grab will suffice?

Thanks/Terimah Kasi!