The road to the mountain top is accessible via car or if you are not confident in driving yourself you can go with van rental, available at the parking area at the foothill. As I understand, the van ticket is RM 8 per person.
The road is easy but there are narrow parts and lots of curves. Some of them are abrupt climb and need good attention and driving skills. The road has some mirrors to help you while driving at the curves, but unfortunately some are missing/vandalised. The road has no street lights. It is recommended to drive during day time.
On the top is the Regency Jerai Hill Resort, The Puncak Restaurant, Cafe Point, Telaga Tok Sheikh, Mushroom Farm (no chance to visit as it was closed) and the Botanical Park.
The View from the top of Mount is outstanding, if the weather conditions are favorable. You will notice the paddy fields, the sea and some parts of the northern Kedah state.
The weather is just wonderful, with temperature comparable to the Cameron or Genting Highlands.
The view and the the beautiful flowers will take your breath.