A cheap way to travel from Penang to Thailand by train is to take the regular commuter service which departs every hour or two from Butterworth Railway Station on the mainland.
If you are staying on Penang Island, you will firstly have to take the Penang to Butterworth ferry over to the mainland, where it is just a short walk to get to the railway station.
Commuter Timetable for 2017 - 2018 (All Trains operate daily):
Morning / Afternoon Timetable
Afternoon / Evening Timetable
Komuter trains are not like the more comfortable Electric Train Services and seating is arranged along the sides of the carriages like a subway train.
For those unlucky enough to not get a seat, you will have to stand in the centre of the aisle.
If you get on at Butterworth, chances are you will be fine and get at seat most of the time, but be warned, this Komuter route is very popular and during busy holidays periods, trains can get packed, especially in the middle section of the route around Alor Setar.
Another thing you should be aware of: there are no toilets on board.
The KTM Komuter trains are the cheapest way to travel in this area of the country.
A ticket all the way from Butterworth to Padang Besar will cost just RM 11.40.
Tickets for these commuter trains are only sold on the day of travel.
Tickets are available from the ticket counter at Butterworth Station, so allow yourselves some extra time to buy tickets, as you may (at busy times of the day) have to queue at the counter.