Drove from Bangalore to Yelagiri via Sarjapur, Kuppam covering NH-219. This will be a great, great trip if you like driving. Getting out of Sarjapur was a big trouble but once out it was a dream. Narrow roads passing through jungles but you will hardly get oncoming traffic. This road is called MDR456. Don't expect to be racing at very high speeds but 50 kmph should be good. Roads are not so smooth but flowing curves and scenic beauty driving along the river in a dense jungle where you won't find any human let alone traffic is a terrific experience.
For Check posts Karavalli, where you have to pay Rs 20 per head to enter the forest area. and there was no strict limit on the time. And try to avoid Bandipur route as the checkpost only open from 6am to 8pm. Mach's Gut!