Abstract
V11X SUMMARY Intercity passenger travel demand analysis is aimed at relating intercity traffic to the socioeconomic charecteristics of the travelers and to the tecnique and the level of service characteristics of transportation system. The fundamentals of the intercity transportation demand analysis rest on the observation of the regularities in the spatial distribution of socioeconomic activities. Intercity travel demand analysis is especially suitable for mode-specific analysis, as it can be assumed independent from all other modes. On the other hand, the analysis of air transportation demand follows in general, two approaches used for intercity transportation: macroanalysis and microanalysis. Macroanalysis is concerned with system-wide air transportation activities and deals with traffic model that are not highly stratified while microanalysis is related to more specific ori jin-destination flow and to highly stratified measures of traffic activity. Microanalysis is appropriate for both time series and cross-sectional data whereas macroanalysis is suitable for only time series data. Some model types used in microanalysis context are: i) city-pair models, ii) disaggregated models, iii) airport-specific demand analysis, and iv) air travel choice models. Most common time series models used in both microanalysis and macroanalysis are: i) simple time series model, ii) the partial adjustment model, iii) the permanent income model, and iv) other time-lagged effects model. In this PhD dissertation, demand for air transportation in the corridors of İstanbul-Erzurum and Ankara-Erzurum is investigated in the context of airport-specific demand analysis. The dissertation comprises four parts. In the first part, intercity passenger demand is studied in general. The second part deals with the approaches for air travel demand and themodels to be built in this context under the heading of the demand for air trasportation. The results of interviews carried out to specify trip behavior for the travels from Erzurum to other provinces are discussed in the third part. Finally, transportation in the corridors of istanbul-Erzurum and Ankara-Erzurum is forecasted at Erzurum airport. The relations between intercity travel and personal income, occupation, education, purpose of travel and choice of mode are separetely detected in order to specify trip behavior. No strong relation is found between the levels of travelers' income and all modes of intercity transportation (rs=0.40, p>0.05) while a perfect relation is seen between the levels of travelers' income and air transportation (rs=1.00). In the travel distribution by occupation, it is observed that businessmen and top executives are coming in the first place in using air travel. Those are followed by independent traders and workers with salary. No significant relation can be found between the level of education and travel with all modes and air travel (the correlations are rs=0. 20,p>0.05, ; rg=-0.30, p>0.05, respectively). Among nine travel purposes, recreational trips and visits for friends and relatives in all travel modes, and business trips in air travel are recorded with the highest incidence. On the other hand, the cost of travel is seen as the most important criteria in all travel modes (% 40.4) while the travel time in air travel (% 90.2). In order to forecast the demand in the corridors, total number of passengers is regressed with the possible combinations of fare per km., provincial incomes, both in total and in per capita, provincial populations and trend variable by using simple time series model in three different forms (lin, lin-log and double log) with employing annual and quarterly data. The variables of provincial incomes and populations are included in the model in forms of lin-log and double log multiplicatively. Therefore, these models become gravity type models.The results of simple time series model forecacting show that none of the models employing annuel data provide satisfactory fitness while models with quarterly data give acceptable results. The model which is based upon the assumption of unity-elasticity in double logaritmic form, and which is relating the total number of passengers to fare per km., provincial income per capita and provincial populations is accepted as the best fitted model in both corridors. Secondly, a partial adjustment model is formed by using the model relating the total number of passengers to fare and per capita income. The partial adjustment model is seen fitted in determining short- and long-run elasticities. Thus, it is seen in both corridors that the elasticities of price are -0.55 and -1.00 while those of income are 0.60 and 1.00, in the short and long runs, respectively. A permanent income model is applied to the model which is regarded as the best fitted in simple time series analysis. As a result, the permanent income hypothesis is rejected. Later, a general time series model comprising both partial adjustment and permanent income models simultaneouly is established. This model doesn't fit enough. In order to test the seasonal fluctuations in relavant corridors, quarterly- and semi annually-dummy variables are included in the models. The semi annually dummy variable model gives sufficient fitness in both' corridors while the other model doesn't. With the former model, the number of passengers in Îstanbul-Erzurum and Ankara-Erzurum corridors is predicted for different pricing policies for a period between 1990 and 1994.
