Manali to Solang valley and Atal Tunnel road stretch witness heavy vehicular traffic during peak summer season. So there is a likelihood of being stuck in a traffic jam resulting in deadlocks of hours.

Gramphu to Batal road is riddled with potholes, waterfalls, rainfed seasonal streamlets and water crossing. It is an uphill road. So it is better and convenient to drive this route downhill.

Also, if you travel through the Manali route, you will be deprived of the scintillating beauty of the Hindustan-Tibet Highway. The serpentine roads amidst naked mountainous terrain is an ineffable beauty in itself.

Unlike Manali route, Shimla route will witness gradual ascent which is healthy for acclimatisation. It is advisable to avail Shimla route as the chances of catching Acute Mountain Sickness is greater in the Manali route due to dearth of time for acclimatisation.

It is a very frustrating affair to withstand the unwarranted drama involved in getting Rohtang Pass permits. However, this can be bypassed through the Atal Tunnel. There is no such issue while traversing through the Shimla route.

If you travel through the Manali route, on the very first day you have to traverse through the rough and inhospitable terrain till Kunzum Pass which may render even an otherwise fit guy prone to vomiting. As the saying goes that the first impression is the last impression, encountering such medical inconvenience on the very first day of the tour runs the risk of putting an otherwise enchanting journey in a lurid light, thereby heavily taxing the vim and vigour of the remainder of the trip.