9.2 WINDSOR TUNNEL [DETROIT] FROMJEFFERSON AVENUE TO CANADA [WINDSOR]:

The tunnel is inherently most vulnerable to hazardous materials due to the limited ability of vehicle occupants to ovoid toxic fumes itn the tunnel. The ventilation system inside the tunnel might contribute to (exacerbate) or impede escape with respect to hozmot incidents. It the ventilation system were kept on, the air supply could ltcomn (my tires and make the conditions in the impacted section of the tunnel worse. In the case of toxic gas and liquid spills, it the ventilation system were kept on, one has to consider the possibility (and resultant consequences) of toxic gases being discharged from, or distributed through, the ventilation system. The dilution of the hazardous materials would be 0 lfunction ot the number of ventilation zones in the tunnel ottected by the release. For spills of toxic liquids, the impact could be significant because gravity would allow the spill to travel toward the lowest point in the tunnel, consequently causing more of the toxic gases to flow into the ventilation system. While the video surveillance system would allow tunnel managers to identity dangerous situations quickly, the number of individuals that might be trapped in the tunnel and the lock of any sate escape portals from the tunnel decrease the likelihood oft escape. Escape portoals are present in most modern tunnels longer thaen 500 meters, but presently not installed in the WindsorTunnel.

PROPOSED RECOMMENDATION:

NOTE: See Table 7 for information regarding Class 6.2 and Class 7.

The route under Cobo Ha0l“l is oa flunction there is a need to protect the adjacent ofl the configuration oft the route that creates a ”de tocto" tunnel, and, as such, downtown area of Detroit, 05 wel”l 05 the highway infrastructure. An explosion under the

under the

building would pose an obvious risk to the building structure

and to people inside and immediately outside of

the the

building, as well as to those on Ihe ottected highway.

well as to those on the ollected highway. Many of the types 0oft plumes tfrom o hozmot release resulting

from

Res t r i ct al l R EC O M M ENDATION: p l a carde d ve h i cles.

9.4 STATE ROUTE M- - T lO [DETROIT] FROM 8 MILE ROAD [SOUTH] TO WYOMING ROAD:

(Explosives) a0nd Class 3 (Flammable Liquids) materials. In the event of o hoczmot release, the vertical walls

surrounding the lowered highway could confine spills ol gas, extend the hazardous concentration farther down the roadway and delay the dissipation of potentially hozord0us plumes. Sole escape routes would be limited to existing loddets olong M-lO's vertical walls, thus limiting sole escape routes for vehicle occupants. The risk would be reduced on road sections that are lowered but with sloped, rather than vertical, walls. Based on oanoalysis of the data, which examined the potential tFor o0 hazardous 9g0a5s (Class 2 material) involved in on accident to combust or vaporize rapidly

- presenting the potential For high risk - - -

Closs 2 (Gases) hazardous materials also should be testriictteecdl.