Final answer:
Freeway and interstate highway crossovers are used by authorized vehicles for emergency and maintenance purposes. The development of the interstate highway system has had significant impact on community structures and commuting patterns.
Step-by-step explanation:
Crossovers on freeways or on interstate highways are used by authorized vehicles, such as police, emergency services, and highway maintenance crews, to perform their duties more effectively and respond to incidents on either side of the highway without having to travel to the next official exit. These crossovers are essential for providing timely responses to accidents, enforcing traffic laws, and conducting roadworks.
The interstate highway system was largely developed after the Federal Highway Act of 1956, which led to an extensive network of roads designed for high-speed travel and the efficient movement of private and commercial vehicles. However, the construction of these highways often led to the bypassing of small towns and a shift in commercial activities away from city centers, affecting local economies.
In Los Angeles, the expansion of the suburban areas and the increasing number of commuters required a robust transportation infrastructure. The interstate highways, with their ability to facilitate long-distance travel and reverse commuting, have played a crucial role in the region's urban and suburban development.