what is logical method 

ans- Transportation planning is a wide human-oriented field with diverse and challenging problems waiting to be solved. Characteristics and performances of transport systems – services, costs, infrastructures, vehicles and control systems are usually defined on the basis of quantitative evaluation of their main effects. Most of the transport decisions take place under imprecision, uncertainty and partial truth. Some objectives and constraints are often difficult to be measured by crisp values. Traditional analytical techniques were found to be non-effective when dealing with problems in which the dependencies between variables are too complex or ill-defined. Moreover, hard computing models can not deal effectively with the transport decision-makers’ ambiguities and uncertainties. In the past several decades a variety of deterministic and stochastic models have been developed to solve complex traffic and transportation engineering problems. These mathematical models use different formulae and equations to solve such problems. During their education and training, engineers are most often directed to the use of exclusively objective knowledge (formulae and equations). However, when solving real-life engineering problems, linguistic information is often encountered that is frequently hard to quantify using ‘classical’ mathematical techniques. This linguistic information represents subjective knowledge (linguistic information).