TomTom has announced that its congestion index has come to South Africa, measuring traffic in Johannesburg, Cape Town, and Durban.
The index relies on anonymous travel time information gathered from its customers, which TomTom said lets them see real-life driving patterns rather than relying on theoretical models.
According to TomTom, they compare travel times during non-congested periods with travel times in peak hours on local roads, arterials, and highways. The difference is expressed as a percentage increase in travel time.
Sample size is expressed in total number of measured kilometres for the period (Q1 2012), TomTom said.
The table below shows the indices as calculated by TomTom:
|Delay per hour at peak||37min||34min||15min|
|Delay per year with 30min commute||87h||83h||46h|
|Most congested day||15 Mar 2012 (Thu)||16 Mar 2012 (Fri)||23 Mar 2012 (Fri)|
|Average free flow speed||63km/h||69km/h||78km/h|
|Average worst peak period speed||56km/h||63km/h||76km/h|
|Total network length||2,590km||788km||1,614km|
|Network length: highways||311km||258km||363km|
|Network length: non-highways||2,278km||529km||1,251km|
|Total vehicle kilometres||4,498,347km||1,008,495km||817,730km|
As might be expected, Johannesburg was rated as the most congested city overall in South Africa for the first quarter of 2012.
It was interesting to see that Cape Town has a higher congestion index on its highways and on weekends, however.
TomTom also included graphs to show which days of the week had the worst (and best) traffic flow.
These are shown side-by-side below, where the coloured bars represent the congestion level with the best and worst periods indicated in green and red respectively: