# Determination of Factors Influencing Road Transport Demand: Evidence from Croatia
## 3 The Impact on Road Transport Demand in Croatia
### Traffic and Transport Factors
#### 3.1.3 Geographical Location  
Geographical location was analyzed according to the national classification of spatial units (NUTS-1, NUTS-2, and NUTS-3) [32]. The use of NUTS 3, NUTS 2, and functional regions allows for a more granular analysis of transport demand, capturing the regional differences that exist between Croatia's coastal and inland areas. This differentiation is critical, especially given the distinct economic drivers of tourism along the Adriatic coast compared to continental area. National classification of spatial units of Croatia is shown in Figure 10. For the purpose of the analysis, the Tukey-Kramer test was conducted, with the initial assumptions being tested and satisfied. A significance level of 0.05 was used, and the null hypothesis was that there is no statistically significant difference in the movement of average annual rates of change in road transport demand across different spatial units. Figure 5: Trend of average annual rates of change in road transport demand intensity for ASDT (source: [29], authors’ processing). Figure 6: Trend of average annual rates of change in road transport demand intensity for AODT (source: [29], authors’ processing). Figure 8: Determining the statistically significant difference in trends of the average annual rates of change in road transport demand intensity based on the road category, ASDT (Tukey–Kramer test). * just indicates statistically significant correlation. Figure 7: Determining the statistically significant difference in trends of the average annual rates of change in road transport demand intensity based on the road category, AADT (Tukey–Kramer test). * just indicates statistically significant correlation. Figure 10: National classification of spatial units of Croatia (a) NUTS-1 (entire Croatia), (b) NUTS-2 (Statistical regions-Continental Croatia and Adriatic Croatia), and (c) NUTS-3 (countles). For the analysis, statistical testing of the difference in means of annual rates of change in AADT, ASDT, and AODT was carried out by counties (NUTS 3) and statistical regions (NUTS 2). For the entire Republic of Croatia (NUTS 1), it was found that there is a statistically significant difference in annual rates of change in road transport demand during the analyzed period (see Figure 1). In addition, testing was conducted according to six functional regions, which according to the Transport Development Strategy of the Republic of Croatia for the Period from 2017 to 2030 [30] reflect a significant portion of daily migrations in Croatia. During the analysis of spatial units, it was also noted that neither NUTS 3, NUTS 2, nor functional regions represent actual economic and transport functional regions of Croatia but rather administrative boundaries. This is demonstrated by significant differences in development (and consequently, traffic intensity) among counties (e.g., the City of Zagreb and other major cities compared to counties without major cities) as well as within counties themselves (e.g., counties in Adriatic Croatia have economically stronger local government units on the coast than inland, as reflected in the average county GDP). In the first step, an analysis was performed at the county level (NUTS 3), revealing a statistically significant difference in the means of annual rates of change in road transport demand for AADT and ASDT. No statistically significant difference was found for AODT by counties (NUTS 3). A more detailed analysis of counties shows that generally higher rates of change are recorded in the counties of Adriatic Croatia, which can be interpreted as being caused by ASDT, i.e., the tourist season. This is confirmed by the fact that significantly greater differences in means between counties were recorded for ASDT.