Source: adapted from Janelle, D.G. 1968 "Central Place Development in a Time-space Framework“, The Professional Geographer Vol. 20: pp. 5-10. Data for 2000 based on expedia.com direct flights.

Regional Space / Time Convergence (in minutes)

The above graphs display a process of space / time convergence between two city pairs, London and Edinburgh (located 520 km apart) and New York and Boston (310 km apart). Both city pairs went through a different space / time convergence process. With the development of stage-coach services in the 18th and early 19th centuries, travel times declined substantially. However, by the 19th century stage coaches have reached their optimal efficiency and could no longer provide time improvements. The development of rail networks initiated a new phase of space / time convergence and by the early 20th century travel times were significantly lower than previous decades. The development of highways and then air transportation systems from the mid 20th century reduced travel times to 100 minutes between London and Edinburgh and to 70 minutes between New York and Boston. It is unlikely that these figures will change anytime soon. Contemporary space / time convergence dominantly takes place at a system wide and global level.