For an example of bad road planning, one need not look beyond Beijing. A city of some 3 million cars and 15 million people, Beijing has traffic flow that would generally be accepted by many as terrible. The problem is due not only to having too many cars on too few roads with insufficient public transportation (as of writing Beijing only has three operational subway lines), but is also compounded by badly designed roads.
Let’s take a few examples.
1. The architect of this road is a complete nincompoop. What we have here is self explanatory – we have a criss cross traffic flow of cars attempting to head up the onramp to the flyover direct from the main road, whilst meanwhile cars on the subsidiary road attempt to get back to the main road. Of course, we also have cars entering the main road from the subsidiary road, and needless to say that any cars stuck behind another vehicle changing lanes, they too will be delayed thus slowing down whole lanes of traffic.
(NOTE: Primary / Subsidiary roads is a common concept in China, where major roads have parallel subsidiaries used as intermediaries for turning onto or off a primary road).
2. This major bottleneck can be found on a flyover not far from GuoMao （国贸) in the CBD area (diagram represents one direction traffic flow only). From a nearby building high up you get an excellent vantage point overlooking this junction (双井桥) and can see exactly where the problem lies – three lanes splits into four, which cars take advantage of, but in the far left lane traffic flow is disrupted by other vehicles joining the overpass, thus causing tailbacks as drivers in lane one must break and/or switch over to lane two or three. It does not help that this process is somewhat repeated about 50 metres down, with lane 1 splitting off elsewhere again.
This junction can easily be improved by maintaining a three lane structure and reserving the additional lane exclusively for cars entering or leaving the junction. Simple lane markings or dividers (possibly more effective in Beijing) can keep other cars out, and will give cars joining or exiting the roads sufficient time to adjust speed accordingly.
3. You’ll find this culprit on the Airport Expressway (机场高速）leading towards town at the junction turning onto the third ring road heading west (北三环路). Yes, it’s a 90 degree turn off a highway – with terrible signage. Needless to say, drivers heading in this direction will find themselves breaking to a near crawl then hastily turning the corner no doubt also causing trouble behind.
Many junctions in Beijing are plagued with the problem of having insufficient headway at the junctions for cars to make speed adjustments. In addition to this, a ‘turn right on red’ rule which just isn’t suitable for China, lights which are green in multiple directions, and two tiered junctions make driving in China so much more confusing – and chaotic. With the majority of air pollution in Beijing coming from traffic, and with idling engines creating 30% more pollution than a moving one, sorting out Beijing’s traffic problem will come a long way to solving it’s pollution problem too.
What Beijing needs now is a much improved public transport network (this they are working on, with the construction now of several new underground lines) – but increased education for drivers is also essential and, more importantly, the design and layout of the road network needs serious review. Many of the problems on the road are just down to bad planning: Beijing may physically have excellent well maintained roads, but if not designed properly, they aren’t useful for cruising at 10km/h anyway.