1. GEOP 4355 Transportation Routing Models
Outline
What is routing?
Why is routing important?
Transportation routing basics
Routing problems solving
Sources/references used in the preparation of this presentation are listed in the Introduction presentation

2. What is routing?
Determining the best path between two points (line) or for a milk run (multiple deliveries).
Factors to be considered
Travel Time : f[congestion, distance, infrastructure]
Delivery windows (when promised / receiving times at the delivery locations)
Pickups (if considering a mix of deliveries and pickups)
Minimize:
Empty Hauling

3. What is routing?
Go to IBM page

4. Why is routing important?
Effective use of assets and workers
Maximize deliveries/resources (outputs/inputs)
Reduce need to replace/purchase new equipment
Reduce maintenance and wear/tear
Meet customer needs
On time delivery
Speed of delivery
Availability for rush orders
Minimize effect on the environment (green transportation – minimize CO2 emissions)

5. Transportation routing basics
Routing complexity elements
Fleet has different types of vehicles with different capacities
Pickups and deliveries in same route
Delivery time windows
Driver safety rules (500 miles, 8 hours,…)

6. Transportation routing basics
Some Principles
Forming clusters (groups in close proximity)
Less total travel

7. Transportation routing basics
Some Principles
Plan starting from farthest point
Teardrop pattern
Plan largest vehicles first
Pickup mixed with deliveries (considering vehicle loading/unloading process)
A stop far from all clusters indicates a need for an alternative means (for example outsourcing it)
Considerations of milk runs versus direct shipments

8. Routing problem solving
Routing: Travelling Salesman Problem
A classical problem in the field of mathematics/ computer science.
Defined in the 1800s by the Irish mathematician W. R. Hamilton and by the British mathematician Thomas Kirkman
It’s the subject of significant study. NP = Non Polynomial.

9. Routing problem solving
TSP: A person/vehicle/… must visit n locations.
The route must start and end in the same location.
A route must visit all n locations.
There is a cost associated with each connection (time or distance).
Hamiltonian Cycle: A route that visits all n locations in a cycle.
Classic TSP: Each node can only be visited once, Practical TSP: can backtrack/return.
DM: the manager of the moving resource.

10. Routing problem solving
Example:
Truck must deliver to 5 customers.
Given: distances between the customers.
Start is location E (although not a relevant issue for the process) B 16 17 5 11 22 24 A E C 7 13 19 D 27

11. Routing problem solving
Solving TSP optimally would require full enumeration.
EBCDAE, EBCADE, ECBDAE, ECBADE, ECDBAE, ECDABE, …4! = 24 combinations.
Heuristics.
Best solution that can be found by a simple method.
An actual solution but not optimal. Want as low as possible.

12. Routing problem solving
Minimum Neighbor Algorithm
Select any node.
Select unvisited node with the smallest distance/cost.
Go back to #2 until all nodes have been visited.

13. Routing problem solving
From B
3 options
D is the lowest distance B 16 17 5 11 22 24 B A E C 16 17 7 13 19 5 11 D 22 24 A E C 27 7
Start with E
4 options
To B is the lowest distance 13 19 D 27

14. Routing problem solving
From A, rest of cycle is set.
Distance =
= 80 B 16 17 5 11 B 22 24 A E C 16 17 7 5 11 13 19 D 22 24 A E C 27 7 13 19
From D
2 options
A is the lowest distance D 27

15. Routing problem solving
Starting from A
Distance = = 69 B 16 17 5 11 22 24 A E C 7 13 19 D 27

16. Routing problem solving
Mixing routings and number of trips
Could include a requirement for multiple trips due to vehicle capacity constraints
Determine the sets of visits for each trip and the route.
Considers multiple transportation rates.
DM: Traffic manager using a 3PL transportation company.

17. Routing problem solving
Three loads to ship from DC: 13K, 18K, 10K. Lbs. to A, B, and C
Rates per cwt mile (cwt = 100 lbs.)
base= $0.032 cwt-mile
S ≥ 15K = $0.023 cwt-mile
S ≥ 35K = $0.015 cwt-mile
TL = $5.9 per mile Max capacity = 45K
Stop-offs = $400 each
Empty haul not an issue for TM
One load with stops
Direct routing with next rate B
340
175
500
250
140 C A

18. Routing problem solving
Ship all loads in a single truck. Route: A → B → C
Total weight of shipment = 41K lbs.
Applicable rate = $0.015/cwt
Cost per mile = 41K lbs. / 100 × $0.015/cwt/mile = $6.15/mile.
Next rate = Truck Load = $5.9/mile. Best use the Truck Load rate.
Total miles = 565
Movement cost = 565 miles x $5.9/mile = $3333.5
Stop-offs = 2 x $400
Total cost = $4,133.5

19. Routing problem solving
Ship all loads separately
Ship to A (13K Lbs.)
Applicable rate = $0.032/cwt
Cost per mile = 13K lbs. / 100 × $0.032/cwt/mile = $4.16/mile.
Next rate = $0.023/cwt
Cost per mile = 15K lbs. / 100 × $0.023/cwt/mile = $3.45/mile
Best to use the next rate = $3.45/mile
Movement cost = 250 miles x $3.45/mile = $862.5

20. Routing problem solving
Ship all loads separately
Ship to B (18K Lbs.)
Applicable rate = $0.023/cwt
Cost per mile = 18K lbs. / 100 × $0.023/cwt/mile = $4.14/mile.
Next rate = $0.015/cwt
Cost per mile = 35K lbs. / 100 × $0.015/cwt/mile = $5.25/mile
Best to use the applicable rate
Movement cost = 340 miles x $4.14/mile = $1,407.6

21. Routing problem solving
Ship all loads separately
Ship to C (10K Lbs.)
Applicable rate = $0.032/cwt
Cost per mile = 10K lbs. / 100 × $0.032/cwt/mile = $3.2/mile.
Next rate = $0.023/cwt
Cost per mile = 15K lbs. / 100 × $0.023/cwt/mile = $3.45/mile
Best to use the applicable rate = $3.2/mile
Movement cost = 500 miles x $3.2/mile = $1,600
Total cost = $ $1, $1,600 = $3,870.1
Current best solution = ship loads separately