Abstract
The holland tunnel, which has a fully transverse ventilation system, had to have its ceiling removed because of concrete deterioration. For more than a year before the installation of a new ceiling, vehicular traffic would continue, and the ventilation system would operate in a semitransverse mode. Evaluations were conducted to ascertain the capability of the ventilation system to maintain an acceptable environment during normal vehicular usage and in the event of fire. These evaluations included computations for varying traffic patterns and actual fire testing. This paper appeared in transportation research record no. 1150, tunneling. For covering abstract see irrd no 818446.