Volunteers are crucial for rescue efforts in a disaster but sensible ones, even more so.

After the magnitude-6.5 earthquake hit Ludian county of Yunnan province on Sunday afternoon, thousands of volunteers drove their private cars to the epicenter of Longtoushan township to help with rescue operations.

But their large numbers strained the local transport system and the rescue itself. Only a 15-meter-wide road provided access to the township. Overnight rain damaged the sole artery and it could not withstand the packed vehicles.

The volunteers carried food and bottled water supplies. I met volunteers on at least four motorcycles and several cars on the way to the epicenter, but we moved about 6 kilometers at most before I finally decided to head for the most damaged sites on foot.

As I walked, I met a man named Wang from the Tongbo charity organization in Ludian. He said he had no idea what he could do for the disaster victims. He just wanted to help in any way he could.

Wang said he also gave up driving to Longtoushan after 3 kilometers "because the way there was filled with cars and motorcycles were also finding it hard to get through".

Many vehicles such as trucks carrying soldiers, relief supplies and cranes had to stop, while numerous people loaded with rescue equipment sat waiting on the ground.

The provincial authorities on Monday ordered those driving vehicles that were not directly related to rescue operations, including individuals and donor enterprises, to get off the road leading to the epicenter. But the movement of rescuers dragged on.

Rescue efforts on Monday had turned to the air. Some helicopters carried injured villagers from the township, while some entered the center of the quake zone with food and water.

Premier Li Keqiang also asked the province to keep the channel to the epicenter clear for soldiers, healthcare workers and the injured to get through.

But the congestion had not been alleviated by 6:30 pm, when I had walked on the road for more than 15 kilometers.

The jam reminded me of the major quake that hit Lushan, Sichuan province, on April 20 last year.

Authorities had set up emergency response systems by that time after the magnitude-8.0 Wenchuan earthquake in 2008. Many volunteers also swarmed into the disaster region then.

I covered the quake last year and I remember clearly that some roads were also affected and blocked by private cars.

An unobstructed road is key in disaster relief. It is the lifesaving channel for victims.

It is good to see many Chinese people volunteering to help during these tough times.

But we still have a long way to go in carrying out rescue operations in a sensible way, and not be driven solely by the blind passion to help.

Cao Yin in Beijing contributed to this story.