I came across a customer the other day who was faced with the following problem. The customer has many trucks on the road. Although the planning of these tracks is nicely optimized, a lot of time (and money) is lost in traffic jams. The customer got really frustrated that despite his road planning system, his business suffers from a severe time loss. Not only do some of the shippings arrive too late, but some of the itineraries could have been better planned if he were capable of taking those traffic jams into account...