You are the incident commander at the scene of an 18-wheel box trailer accident with an automobile on a limited access highway (turnpike, superhighway or toll road) at the height of the morning rush hour. The highway is a major commuter artery and any shutdown will have a tremendous impact on traffic flow throughout the region. In addition, it is a very hot and humid day with a temperature of 98 degrees and a relative humidity of 85%.

The first arriving emergency services unit reports the following:

There are no injuries. The driver is standing by the vehicle.
The overturned tractor trailer is placarded dangerous.
There are no visible clues (i.e., leaking, vapor clouds) indicating any breach of containers.
The vehicle driver reports that he is transporting supplies between government military warehouses in the region, including several different hazardous materials.
The driver has ascertained that no munitions or explosives are involved.
The shipping papers that have been located indicate no highly toxic or reactive chemicals, although they are in somewhat disarray, as the driver reports that he had left them on the seat and had not even had a chance to really look at them.
Within an hour the regional state police supervisor arrives on scene and requests the highway be partially reopened. While you have a good working relationship with the state police, you have not had a prior opportunity to meet this supervisor because he/she was recently transferred to this jurisdiction.

The supervisor thinks the highway should be reopened based on the following facts:

There are no munitions involved.
The shipping papers indicate no highly toxic or reactive chemicals.
There are no visible signs of a container breach or hazmat release.
The secondary and tertiary traffic problems being created by the total shutdown of the highway are creating a worse public safety hazard than the overturned truck.
The police supervisor understands your concerns for the safety of the community and the responders. Nonetheless, he/she also predicts that there will be many heat related medical problems and additional accidents if citizens are stuck in traffic for hours.

Discuss

Given the situation and conditions, consider your choices from a risk-based response viewpoint. Summarize your hazard and risk assessment including how you got your information, and then make a decision about how would you respond to the supervisor's request to open the highway. Who has jurisdiction? What if he/she threatens to arrest you? (He/she has made some legitimate points concerning life safety that need to be addressed regardless of whether you agree or disagree with the recommendation to open the highway).