Shows the wide variety of vector formats that open layers supports.
Green Polygon is the maximum extent of the fleet's dispatch zones (i.e. if they happen to have a car in the area)
Yellow Polygon is the extent of the validity of the fleet's promocode (i.e., they are likely to have a vehicle present)
White Polygon is the are of exclusivity for overlapping fleets (if no other fleets nearby, this is likely the same as the yellow polygon)