Why is the

The density of the customer population of a service centre is high near the service centre but decrease with increasing distance, due to the frictional effects of the distance.

This is because customers are more likely to visit a service centre that is closer to their location due to the convenience and accessibility it offers. As the distance from the service centre increases, customers may be less inclined to travel that far, resulting in a decrease in density of the customer population. Frictional effects, such as time and cost associated with travel, play a role in this trend as customers are less willing to overcome these barriers the further they are from the service centre.