The intensity of the interaction between a city and its neighbouring towns and villages declines rapidly with distance from the city. Thus, people from nearby villages, within a distance of four to five kilometres, may commute daily to the city for work, shopping, education or entertainment. Farther away, a decline in the number of people commuting to the city (in both absolute as well as relative terms as well as in the frequency of movement of individuals to the city is noticed. Beyond a certain distance, which varies from city to city and is dependent on modes of transportation, daily movements are replaced by weekly or even irregular movements until ultimately such movements to the city become rare or absent. Apart from the effect on daily or periodic commuting to the city, the effect is also seen in the distribution of goods and services from the city to the surrounding villages. Similarly, the quantum of milk, vegetables, flowers and so on, coming to the city from the villages is also subjected to distance decay. Similar effect will be noticed in case of hospital patient’s or students attending school. The distance decay effect extends from the city to the outer limits of the city region. At this point the quantum of interaction becomes insignificant.