I think in the Andhra route at least the route have either 110kmph mps or 130kmph. I am not sure if there is any stretch with less than these mps where VB is running. I could be wrong here. In Kerala, TVC-Kollam is 100, Kollam-ERS/ERN is 90kmph. ERS-TCR is 80kmph. TCR-SRR is 80kmph and SRR-MAQ is 110kmph....This is wht I have heard. Hence I am not so sure whether introducing VB with such speed restrictions can be beneficial.