8.3.1 IiDENTlIFICATION

OF POTENTIAL CONSEQUENCES

BASED ON

HAZARDS

B a s e d o n T O a cci de n t s c e n a r i o s,

aoanaolysis was performed. The scenarios, which

are presented in certain hazardous materials that could serve as "triggers" for these

these analyses wweerree compared with 0 base risk ossessmenl ot the results oft the risk onolysis, augmented by other aspects oft ItIhe research and 10 thorough review, indicate which classes

these accident scenarios, each oft the tToour routes in Wayne Countly were oanaoltyzed.

analyses with base risk assessment of the some 10 scenartios

of hazardous materials shout|d be restricted ftfor each of the tToour routes, and the potential for risk to human lifte, the environment, property and

Table 6.

Accident Scenarios

Boiling LiquidEXxpunding Vapor Explosion

8 . 4 RO U T I NG MET HODOLOGY F O R S EL E C T E D ROUT E S

the Ttoour Wayne County routes.

The next step

was to

estimate the number of hazardous materials accidents that might occur on the route segments being evaluated.

The

two

discriminating Ffaacttors were route length and hoazmoat carriert accident rate differences.

For oil the reute

segments analyzed,

restricting (prohibiting) Class 3 (Flammable Liquids) hazardous materials shipments higher frequency of accidents involving Class 3 hazmat carriers outweighs the higher consequences of the other classes and divisions of hazardous materials. It transportation of previously

would result in the biggest risk reduction. This is because Class 3 materials represent more than halt ofi the hoazmoat shipments documented in this study. Although higher TtToottaolliity rates are protjtected for other classes of hazardous materials, the higher frequency of accidents involving Class hozmot

ot previously restrticted hazardous materials was allowed
on Wayne County routes, a safeguard could be added by requiring that the hoazmoat shipment motor carriers travel with an escort vehicle or vehicles. iIn addition to esco'rting, another precaution could be added to close the particular route segment being used ftor 0a short, controlled distance aond/or ftor a specified period of time.