This research describes the growth of the Minneapolis Skyway network and aims to determine if the growth of the system followed a logical (i.e. mathematical) path. The paper hypothesizes that the system expanded to where it was valued the most. The point accessibility of each block lying within and adjacent to the connected system for each expansion year is calculated and used to predict the expansion of the skyway system. In order to determine how often the expansion connected the blocks with higher accessibility, a connect-choice logit model relating the probability of joining the network (in a given year) to accessibility measures and network size was employed. The results disclose accessibility is a significant explanatory factor of network growth but the estimated model is not sufficiently good to predict the growth of the network (because of the low pseudo R-squared resulted). Thus, a network growth simulation model was then developed based on the strongest-link assumption (i.e. each time a link was constructed, it was ranked the highest in terms of increasing accessibility between the two blocks it connects). The results show that the simulation model performs well in predicting the sequence of skyway additions based on the strongest-link assumption, suggesting that although various physical, economic, and legal factors may have played a role, accessibility does remain an important factor in predicting which links are connected during the growth of the Minneapolis Skyway net- work.
Samenvatting