1. Traffic Congestion
Overloading is the primary cause of congestion. Patterns of land use and transport infrastructure influence traffic flow. While both commuter and freight traffic contribute to congestion, passenger movements are the main source of gridlock in urban areas.
Motorists in the 21st century spend three times longer in traffic than drivers did a few decades ago. Large numbers of single-occupancy vehicles add to traffic volume. The resulting congestion contributes to air pollution, inefficient use of fuel, and slower commutes, which makes urban life frustrating. Drivers contend with obstacles like buses, delivery trucks, and service vehicles, to searching for parking spots near their destination.
2. Long Commutes
Growing populations, roadwork, and the distance between homes and workplaces all contribute to increased congestion and longer commute times. Expanding road capacity is not always effective for shortening commute times, as it cannot keep up with the growing volume of traffic. New highways can actually result in longer commutes, as they encourage more vehicles to use road networks, increasing overall vehicle-miles-traveled (VMT).
Residential affordability also affects commuting patterns. While most employment opportunities remain in city centers, suburban housing is more affordable. Thus, cheaper housing comes at the expense of longer commuting time.
3. Sprawling Cities
Decentralization makes urban transport systems more complex. As cities expand outward, and distances increase between residences and places of work, congestion becomes a bigger problem for communities and commuting times a major burden for individuals.
Urban sprawl makes public transportation systems more expensive to build and operate and restricts pedestrian movement. Large-scale superstores, and other facilities serving large catchment areas, are not easily accessible by foot, and this encourages the use of motor vehicles.
4. Secondary Infrastructure
Demand for bike and pedestrian infrastructure is increasing, as more people choose to walk or cycle to work. However, many cities were built for cars and are not bike or pedestrian friendly. Bicycle lanes and wider footpaths make riding and walking safer and can help control traffic, but such infrastructure comes at the expense of roadway capacity and parking space.
Access to public transport often requires parking infrastructure. Suburban stations can provide parking spaces for riders to promote public transit usage. Commuters can use these suburban stations to avoid the inconvenience of parking in the city.
5. Large Fleets, Large Costs
Urban transport agencies face challenges when managing large fleets of vehicles and a growing workforce, including maintenance costs, recruiting and retaining skilled employees, and meeting task requirements. Agencies must train their workforce to increase safety and reduce accidents.
Fluctuating demand for public transport poses a dilemma for public transport operators, who must determine the size of their fleets. A fleet large enough to meet peak-hour demand is not economically viable when operated off-peak. However, if operators don’t provide enough vehicles, they cannot support the volume of passengers during peak hours.
6. Parking Difficulties
Drivers stuck in traffic while looking for a parking spot contribute to urban congestion. Cities struggle to provide sufficient parking space to serve central business districts (CBDs). Large car parks consume expensive real-estate, while street parking takes up lanes that could be used for moving traffic.
7. Negative Environmental Impacts
Automobile dependency affects the quality of life of residents, including public health. Cars and related infrastructure have a visual impact on cities. Air pollution, including greenhouse gas emissions, increases alongside vehicle-miles traveled (VMT). Road networks consume between 30 and 60% of metropolitan land, and their territorial imprint grows as more people use private cars. Traffic generates noise and fumes that make walking in urban areas unpleasant. Prolonged exposure to these fumes, especially if the engine is inadequately maintained, is hazardous to health. Fumes emitted from cars contain carbon monoxide, aldehydes, unburnt hydrocarbons and other gases and deposits like tetra-ethyl lead, nitrogen oxides, and carbon particles.