  Measuring the interaction between cities is an important research topic in
many disciplines, such as sociology, geography, economics and transportation
science. The traditional and most widely used spatial interaction model is the
gravity model, but it requires the parameters to be artificially set. In this
paper, we propose a parameter-free interactive city choice (ICC) model that
measures intercity interaction from the perspective of individual choice
behavior. The ICC model assumes that the probability of an individual choosing
to interact with a city is proportional to the number of opportunities in the
destination city and inversely proportional to the number of intervening
opportunities between the origin city and the destination city, calculated
using the travel time in the transportation network. The intercity interaction
intensity can be obtained by calculating the product of this probability and
the origin city's population. We apply the ICC model to measure the interaction
intensity among 339 cities in China and analyze the impact of changes in the
Chinese land transportation network from 2005 to 2018 on the intercity and city
interaction intensity. Compared with the previously widely used spatial
interaction models, the measurement results of the ICC model are more
consistent with the actual situation.
