Mixed Vehicle Routing Problems with Backhauls(MVRPB)

This data set contains 42 problems. The problems have been created 
from Christofides CVRP problems by following the description in: 

S. Salhi, G. Nagy, "A cluster insertion heuristic for single and
multiple depot vehicle routing problems with backhauling", 
Journal of the Operational Research Society (1999) 50, 1034-1042.

Salhi & Nagys original problems are no longer available, 
therefore it was neceassary to recreate the problems. The problems
have been used in the paper:

S. Ropke, D. Pisinger, "A Unified Heuristic for Vehicle Routing 
Problems with Backhauls", submitted to European Journal of 
Operational Research (2003).

The files should be read as follows:

<Number of customers = n>
<Number of depots (always 1)>
<Number of vehicles>
# Then folows a line describing the depot:
<X coordinate> <Y coordinate> <Max route duration> <Vehicle capacity>
# Finally n lines follow. Each of these lines describes one customer:
<X coord.> <Y coord.> <Delivery> <Pickup> <Visit duration>

where "Delivery" is the amount of goods delivered to the customer and
"Pickup" is the amount of goods picked up at the customer.

Distances and travel times are calculated by using euclidean 
distances. Double precision calculations should be used when 
manipulation distances and travel times.


Regards,

Stefan Ropke
DIKU, University of Copenhagen, Denmark
email: sropke@diku.dk