The article will deal with examining relation and quantification of transport service quality impact in road freight transport. First of all, we need to know what the quality exactly means and then we are able to define the quality in transport field. It is important to evaluate quality characters for future of organizations and also to know how to improve their services and products and have a stable position in the transport business. The impact of transport service quality on the performance of road freight transport is necessary to quantify a level of service quality but also define and objectively evaluate the performance of road freight transport with help of an appropriate set of performance indicators and methods. For examining relation and quantification of transport service quality impact in road freight transport it is necessary to apply an appropriate method. The article includes also practical application of the method.