Technology29.09.2012

Traffic congestion: best and worst cities in SA

By Jan Vermeulen

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:

Dimension	Johannesburg	Cape Town	Durban
Rank	1	2	3
24/7 congestion	32%	27%	16%
Highways	18%	23%	13%
Non-Highways	39%	33%	26%
Delay per hour at peak	37min	34min	15min
Delay per year with 30min commute	87h	83h	46h
Morning peak	88%	82%	45%
Evening peak	65%	56%	45%
Weekdays	37%	31%	19%
Weekends	13%	17%	8%
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: