[saubi2299]

If anyone is planning to go to Shimla from NCR, all traffic is diverted to the service lanes at Delhi-Sonepat border, which eats up 20 minutes atleast. Thereafter, traffic is diverted to villages after Ambala, which can waste up to 1 hour. Had to go through the narrow lanes, but everyone remained disciplined and stuck to their lane, without any honking.
Route from Panchkula to Shimla is same as 2 years back, with 2 of the 4 lanes closed at many places due to minor rocks falling. So, stick to the speed limit as you will have to often change lanes.

Another option is to take Shahbad-Saha-Panchkula route, which avoids the Ambala diversion. This is a good 4-L Highway, except for the 1 km stretch at Saha.

If you are travelling in evening and even late nights, avoid going through Delhi and take KMP/KGP depending on where you are. Lots of construction going on near Airport and on Ring Road, and as the construction is on full swing during night, it takes more time than predicted by Google.