Hi.... i just got back from a Bangalore - Thrissur round trip (literally). Since I was confused as to which road to take, I went by this route
Bangalore - Mysore - Wayanad - Thamarassery - Areakodde - Manjeri - Perinthalmanna - Pattambi - Thrissur
The road was good in about 80% of the places. And about 10% decent. But the remaining 10% is nothing short of disastrous! We left Bangalore at 6:30 in the morning and reached Thrissur at around 6:30 pm..... 12 hours (including breakfast and lunch break and a tyre change due to a puncture) and a distance of about 480 kms.
I came back through this route.
Thissur - Palakkad - Coimbatore - Bhavani - Mettur - Thoppur - Dharmapuri - Krishnagiri - Hosur - Bangalore
This route has about 90% of good roads, 5% decent roads and 5% of SUV test tracks. Left Thrissur at 3:45 pm and reached bangalore at 1:45 am the next day...... 10 hours of drive (including dinner and repairing the punctured tyre) and a distance of.... you wont believe it..... 480 kms!! The drive was good till I hit the NH after Thoppur. It was raining hard and it seemed like all the fully loaded trucks in South India decided to have a race! But the rain eased off once I reached Dharmapuri and the rest of the drive was uneventful.
My suggestion: Take the Thissur - Palakkad - Coimbatore - Bhavani - Mettur - Thoppur - Dharmapuri - Krishnagiri - Hosur - Bangalore route. That is unless if you are a nature freak, driving during the day and want to see sights like this.
Before Bandipur:
Ghat section after Wayanad: