Fatma Gzara

Whenever Fatma Gzara passes a “no trucks permitted” road sign, her own wheels start to turn.

The management sciences professor knows the sign is intended to keep trucks carrying dangerous goods, also known as HazMats, off the route and to keep people living and working in the surrounding area, safe. But how will the trucking company respond to the request?

This is the kind of scenario Gzara is working on addressing. The new faculty member uses bilevel mathematical modelling to determine how road networks are most likely to be used by couriers of hazardous materials.

The challenge, she says, is taking into account two decision makers with conflicting objectives. The government decides which road networks are the least risky – the roads that are straight or don’t run through populated areas. Government officials open and close various roads to create the network that is most likely to mitigate the risk. Meanwhile, trucking companies are trying to find routes that pose less risk and minimize costs.

Bilevel modelling is complicated and time-consuming, but Gzara says she enjoys working with real data. Besides, the results are worth it.

“It’s easy to construct examples where if we don’t use this way of modelling the decision making process, the results can be catastrophic,” she says.