Vehicle Routing, Round 2

Road networks are complicated bastions of all manner of spatial quandaries, most notably, for our purposes, those involving vehicle routing.  There is no end to the permutations of various circumstances these kinds of problems can involve, and knowledge of some of their more common manifestations is invaluable.  When these problems involve ordered pairs of pick ups and drop offs, there are a multitude of parameters we can specify to maintain various characteristics of our intended route- time windows, driver breaks, wheelchair access (if required), distance, etc.  According to the specifications we input the actual resulting route can vary widely.

Above is one solution (series of routes) to a routing problem involving pick ups and drop offs of people at locations in south Florida. The parameters used to create these routes include drop off and pick up time windows, maximum working hours and breaks for drivers, and route zones, which constrain where certain routes can travel.  The initial routing solution created for the above had constraints which produced an output with five "unassigned" locations, which were not assigned to any of the routes.  The second solution, shown above, modified the parameters such that two additional vehicles/routes were included, which eliminated the unassigned locations.  The customer service aspect of this modification is notable with regards to this routing problem- the ability to include all of the desired stops, which the second set of routes (above) does, increases the number of customers served, which is obviously beneficial.  Additionally, the extra routes may relieve some of the burden on the rest of the vehicles, allowing more flexibility in service times, which also benefits the customer.