Which change to policing occurred due to the introduction of automobiles between 1900 and 1940?

The introduction of automobiles into policing between 1900 and 1940 significantly improved the speed at which police could respond to calls for assistance. Prior to the widespread use of cars, officers relied on foot or horseback, which limited their range and the time it took to reach a scene of a crime or emergency. With the advent of automobiles, police could cover much larger areas in a fraction of the time, leading to a more rapid response to incidents.

This faster response time translated to not only quicker intervention in situations where immediate action was needed, such as in the case of crimes in progress or emergencies, but also improved police visibility and presence in the community. This capability helped establish a more effective policing strategy, particularly in urban areas where crime rates were rising during that period.

While community engagement might have been impacted in various ways due to the changes in police mobility, it was not a direct consequence of the automobile's introduction. Similarly, reduced crime rates would require a myriad of factors outside just quick responses to be effectively attributed to automobiles, and enhanced physical fitness among officers was not a specific change triggered by vehicle use. Therefore, the most clear and direct impact of automobiles on policing during this time was the increased speed of call response.