ABSTRACT
The 500 km-long six-lane Tomei and Meishin expressway No. 2 (hereinafter referred to as “New Tomei and Meishin expressway”) will be a trunk line for the 21st century, connecting Tokyo, Nagoya and Kobe, along with the existing Tomei and Meishin expressway. The expressway will be constructed to the highest standards, designed for an optimal speed of 140 km, in light of improved vehicle performance and an increasing demand for highways that can accommodate high-speed driving. To ensure safe and comfortable driving conditions, the highway is horizontally aligned, with a large width and gentle longitudinal gradients. As it passes through mountainous areas, about 25% of the highway’s total length will be in tunnels. This paper discusses the maximum exhaust concentration for a safe driving environment, a ventilation system to accommodate the emission control standards which will be intensified, and a ventilation system design that utilizes the space near the tunnel ceiling.
