India, Aug. 17 -- Peak-hour traffic slowdown is no longer confined to the metros, and the length of roads may not always determine which cities cope better, a WRI India analysis of road networks across 20 cities has found.

Every Tier 1 city in the study loses more than half its free-flow speed by peak hour. Delhi's fall is the steepest in absolute terms, from 46 kmph to 19 kmph. Hyderabad and Mumbai both drop from 40 kmph to 15 kmph, Bengaluru from 38 kmph to 13 kmph, and Kolkata from 29 kmph to 11 kmph - the lowest peak speed recorded among all 20 cities in the study.

Tier 2 cities post smaller absolute drops but follow the same pattern. Jaipur falls from 38 kmph to 14, Lucknow from 36 to 15, Indore from 31 to 12.

WRI India says the d...