Face to face and telephone interviews as competing yet complementary methods to elicit information

Face to face (intercept/at home) and telephone surveys have been thoroughly investigated in the service industry literature. Regardless of this, the so far limited studies in the public transportation sector do not state clearly which method yields the better results. Besides, evaluating the more appropriate data collection mode is a complex task, due to the many constraints imposed (e.g. time, budget, and so on). This paper will critically compare the results of two different surveys conducted in 2012 within the Cagliari metropolitan area by the local transit agency CTM, with the chief goal to evaluate which of the two administration methodologies produces the more reliable results. A total of 500 fairly long interviews with CTM’s users and 714 short interviews with non users were collected through the telephone survey, whilst the on-board intercept survey resulted in 3173 interviews. The most significant strength of the telephone methodology referred to the possibility to reach non users and to elicit information on the reasons behind their decision to rely solely on private transport. On the other hand, the main strongpoint of the on-board methodology has regarded the high representativeness of the data collected, rich in information and qualitatively reliable. Therefore, the two approaches do not exclude each other, with on-board and telephone surveys that might be targeted at users and non users, respectively. Finally, this paper is expected to improve the knowledge of existing and likely demand for bus operators and offers valuable lessons for public transport agencies worldwide.