Photo taken on 17th Apr. 2009

As a 60-mile-long traffic jam on a Beijing-bound “expressway” snails along into its 10th day — either easing up now or destined to drag on into September, depending on which report you read — it is worth taking a second to note how this can happen. Road construction is one of the immediate causes, but that in turn is necessary because of increased cargo traffic on the roadway, reports Global Times. What’s that cargo? Coal, in a country where the vast majority of electricity still comes from coal.

Bloomberg reports of the Beijing-Tibet Expressway backup:

Inner Mongolia passed Shanxi province last year to become China’s biggest coal supplier after the government closed mines on safety concerns following a series of deadly accidents in Shanxi. A dearth of railway capacity connecting Inner Mongolia to port cities such as Caofeidian, Qinhuangdao and Tianjin, where coal is shipped to power plants in southern China, has forced suppliers to rely on trucks.

“The situation may ease in three or four years, when rail capacity from Inner Mongolia to Caofeidian gets upgraded and the new rail line to Liaoning province starts,” David Fang, a director at the China Coal Transport and Distribution Association, said by telephone today.

You read that right, three to four years until this freight situation improves. And as the Global Times casually noted, a backup earlier this summer on the same roadway (I decline to use the term “expressway” again here), “reduced [traffic] to a crawl for nearly one month.” The English-language Chinese newspaper’s entertaining story on this jam is worth reading.

The coal-traffic effect is obvious to anyone who spends a little time in one of China’s coal-mining provinces. If you are unfortunate enough to end up on a road near some sizable mines, you risk facing a daylong traffic jam without warning. When reporting two years ago in Shanxi province, the then-coal king of China, I had to pass up a visit to one coal mine when I was told it could take a day to get there (and/or a day to get out), despite being about 50 miles away.

Obviously less dependence on coal would help, and we know all about China’s push to increase nuclear and solar and wind capacity. And one of the big arguments in favor of China’s massive upgrade and expansion of its rail network is, rather than the need to carry more passengers at higher speeds, the seemingly more pressing need to provide more overall cargo capacity, especially for coal. That should not only make the companies helping China with its rail projects happy, like Siemens and General Electric, it will make a lot of drivers happy too.