No. Its not 20 kms extra. From my home in Chennai at East Tambaram to my home at Salem, the total distance is 375 Kms if the Krishnagiri route is taken. If I take the Ulundurpet route, the distance shrinks to 315 Kms. Added advantage of taking Ulundurpet route is, less tolls and no toll between Ulundurpet and Salem. Anyday, I prefer this route than the Krishnagiri option.