Using quantitative assessment in transport is a long tradition in the evaluation of alternatives operating within long planning horizons. It transforms transport appraisal from a restricted project assessment to the foundations for the integrated appraisal of transport planning activities.
With the growth of computers, the study of networks moved into a new phase that focused on the development of efficient algorithms to solve optimization problems in routing. Networks were no longer just a collection of nodes and arcs; arcs now included numeric values, which could represent either distance or time.
In the 1970s operations researchers began to study two classes of vehicle routing problems, the traveling salesman problem and the Chinese postman problem. One class of problems involves an individual or vehicle traveling along the shortest route from node to node, visiting every node in the network and then returning home to its base. (The 19th century mathematician William Hamilton first posed the question of the existence of a circuit that visited each node once and only once.) This problem is called the traveling salesman problem (TSP), as it represents the challenge facing a salesman who must travel from city to city and return home. It is part of a broad class of problems for which we know it is NOT possible to develop algorithms that are guaranteed to find the absolute optimal solution in a reasonable period of time.
Instead, operations researchers work on developing heuristic algorithms that search for good or near optimal solutions. These algorithms generally have two phases. The first phase attempts to find a good initial solution. The second phase involves minor modifications to the best solution found so far in order to create better and better routes.
Quantitative Research can be used in many cases to produce analysis and results that are representative and.......
