China's transportation infrastructure has been developing at breakneck speed. In the past, travelers only had the option of flying to remote destinations. Now a dense network of high-speed railroads crisscrosses the country, cutting travel time significantly.

A 4 trillion yuan cash injection by the central government in the aftermath of the 2008 financial meltdown resulted in new transportation links being constructed at lightening speeds. Mushrooming transportation projects backed by heavy investments have changed the rhythm of life in just few years. They have also become an important indicator for assessing the government's governing capacity. The efficiency of construction has surprised many and at first glance, it seems as if there is nothing that Chinese construction workers cannot build.

Zhang Zanbo, an independent filmmaker, spent three years documenting a highway construction project in the central province of Hunan. The film titled The Road shed light on an aspect of our society that is beyond the imagination of most ordinary people.

Its main cast involves real-life construction workers, local residents, government officials and gang members. The plot reveals how all of them are bound together by a complex web of interest related to an unfinished road.

The project contractor tries everything possible to ease local residents' discontent and win official support in order to push forward the construction work. The camera recorded the stories that we might have read briefly in some news reports.

I've heard many stories about the struggle, conflicts and dirty deals surrounding this kind of massive projects. But The Road, for the first time, allowed me to witness what really happens. One strand of the story highlights the conflict between a few locals and the construction company, which leads to a violent confrontation between workers and local gang members that had other sinister interests. One worker is seriously injured.

The documentary doesn't include the violent brawl, but the director shows its aftermath. We see injured migrant workers lying on hospital beds with frustration on their faces. A relative who came to visit a hospitalized worker, showed one of his own hands, where a few fingers were missing, and said he had also been a migrant worker and was seriously hurt in a construction accident.

This wild growth has left permanent scars on these workers. But what makes me more distressed are those invisible scars that have been left on everybody that is part of the system. The project manager has to keep working to complete the project and try everything possible regardless of the bottom line. Some local officials break laws and cross ethical boundaries to seek personal gains. And the residents, who haggled for better compensation, were trying to protect their own interests.

The Road exposes a part of our society where there were no friendships, trust, ideals, sympathy or understanding. It is a system where everyone hurt each other and the only way to keep it running was to promote personal interests through unspoken rules.

I watched several independent documentaries recently on different themes, but all of them reflected this brutal reality in a similar way. Watching these films have left me with a deep, permanent scar.

The damage caused by big construction projects is much greater than we thought. How should we heal the scars and restore society after being ripped apart? A government order, some compensation or a court verdict is apparently not enough. It is a question for everyone of us to think about.

Zhang Zhaowei is the chief producer at CNEX Foundation Limited, a non-profit organization that produces and promotes independent documentaries in China