If one intends to drive from Mumbai to Kolkata, the ideal route is via NH3 (upto Dhule), NH6 (upto Sambalpur, Odisha), NH42 (upto Manguli, near Cuttack), NH5 (upto Balasore), NH60 (upto Kharagpur), NH6 (upto Kolkata).
The route via NH3 and NH6 is:
Mumbai - Nashik - Dhule - Khamgaon - Akola - Amravati - Nagpur - Durg - Bhilai - Raipur - Areng - Saraipali - Bargarh - Sambalpur.
Driving distance from:
Mumbai (Gateway of India) - Thane - Igatpuri - Nashik via NH160 (erstwhile, NH3) = 180 kms.
Nashik - Dhule = 160 kms.
Dhule - Jalgaon - Bhusawal - Khamgaon via NH6 (new, NH53) = 220 kms.
Khamgaon - Akola Airport via NH6 = 58 kms.
Akola Airport - Amravati via NH6 = 90 kms.
Amravati - Nagpur (crossing of NH6 and NH7) = 170 kms.
Pune, Ahmednagar, Aurangabad, Buldana drivers will touch NH6 at Khamgaon.
After reaching Sambalpur, it's best to avoid driving on NH6 via Deogarh, Keonjhar, Baharagora, Chichira, Kharagpur because it's not a pleasant drive through a predominantly double laned road with uneven surface.
From Sambalpur, it's best to follow NH55 (erstwhile, NH42) from Junction with NH6 to Junction with NH16 (erstwhile NH5) at Manguli near Cuttack via Rairakhole - Angul - Dhenkanal bypass - Chowdwar (261 kms).
NH55 (erstwhile, NH42) is mostly good double laned road barring a few sections where it's also four laned.
Strictly avoid driving the Sambalpur - Angul (140 kms) double laned highway which passes through dense forest section after sundown. Facilities are almost non-existent. However, an early morning drive from Sambalpur to Angul is a great feeling with the sunrays peeping through the tall saal trees.
Angul became famous since mid 1980s for Asia's largest Aluminium smelting plant owned by NALCO Ltd, a Government of India enterprise.
From the Manguli crossing of NH55 with NH16, follow NH16 via Manguli toll plaza - Chandikhole - Bhadrak - Soro - Balasore.
From Balasore (Phulwari Chowk) drive on NH60, a newly relaid concrete road via Jaleshwar, upto Kharagpur which is 123 kms away.
Kharagpur to Kolkata is almost entirely six laned NH16.
Day 1: By leaving Mumbai by 4.30am, a sedate driver/ rider should be able to reach Amravati or an additional 100 kms upto Nagpur.
Day 2: Amravati/ Nagpur to Sambalpur .... good hotels are available.
Day 3: Sambalpur to Kolkata (either via Angul, Bhadrak or via Deogarh, Keonjhar, Baharagora).
Edit: Roadies can drive Mumbai to Kolkata via Pune, Hyderabad, Vizag, Bhubaneswar and follow the map in the link.
https://indian-roadie.blogspot.com/2020/12/indian-roadie-preferred-route-motoring.html
