It is not easy to wake a coal truck driver at 2am, but I had to do it at least twenty times last night to get home from the massive traffic jam on the border between Hebei and Inner Mongolia.

Several miles ahead, the roads had been cleared but the drivers had spent so long motionless that most of them had long since switched off their engines, turned off their headlamps and curled up in their cabs to sleep. We were stuck behind their snores.

At its peak, the snarl up on the G110 motorway was called the "biggest traffic jam in the world" and it may well have been for much of the past 10 days, when the tailback stretched about 60 miles.

But the fact that almost every vehicle in the jam was a coal truck and almost every driver said they were used to mega-jams suggests the congestion was as much caused by the strains on China's energy supply as its transport system.

In recent years, G110 has become one of the busiest – and quite possibly the biggest – coal haulage route in China (and therefore the world).

Almost all of the drivers I spoke to were on their way from mines in Inner Mongolia, which last year became the biggest coal-producing region in the country.

The previous holder of that dubious title is neighbouring Shanxi province, which is faced with such a huge bill to clean up the environmental mess of its mining industry that it has slapped a hefty excess road toll fee on coal trucks. Rather than pay, haulage companies would rather have their drivers stuck in a traffic jam on a cheaper road.

This demonstrates the massive waste (and potential for efficiency gains) in the energy and transport industries, the need for more renewable power. It also shows the often unaccounted for cost of coal (best illustrated in this Greenpeace report), which accounts for about 70% of the country's energy supply and 40% of the freight on an overburdened rail network.

But there are signs of change, even on G110. While the traffic south was jammed with coal trucks, the most striking sight in the opposite direction were several long convoys of taking giant wind turbine blades up to the grasslands and deserts of Inner Mongolia. The Beijing Times today also published pictures of a traffic-beating electric bus that is being designed in China to glide above jams.

Shenzhen Huashi Future Car-Parking Equipment to build this futuristic bus "3D Express Coach" that cars can drive under, August 25, 2010.

In the future, even coal is likely to get a little cleaner – in transport if not carbon emission terms – as China ramps up plans to gassify the fuel inside mines and then pipe it to the final destination.

This will become increasingly important in the future when the bulk of production shifts to the remote western region of Xinjiang, which contains 40% of the country's known coal reserves.

Using roads to transport coal 4,000km from there to coastal ports and factories would probably make today's multi-day traffic jams look like a walk in the park.

In any case, the poor coal truck drivers of China seem to be inured to a life of delays. Early this morning, nobody seemed to mind being woken up in the middle of a motionless motorway with a rap on the cab door. Having spent most of their working life travelling up and down – or being stuck on – this crowded coal artery, they were used to it.

As for me, I was exhausted. Even after rudely awakening drivers every few hundred meters to clear the main jam and get on a less congested lane, it still took seven hours to complete the 130 mile journey home. Compared with the coal drivers, I counted myself lucky.