The development of complete and efficient alternative transportation systems is an important step in reducing the environmental impacts of travel. Alternative transportation systems lead to reduced carbon emissions and fossil fuel consumption while minimizing the need for the replacement of greenfields with road networks. Many individuals associate alternative transportation with a reduction in mobility and convenience. However, if integrated into sustainable city planning practices, such as mixed use development and urban concentration, alternative transportation can actually increase public access to goods and services, while decreasing the amount of time and distance for travel. Some of the more popular forms of alternative transportation are public transit, walking and cycling.

Public Transportation
Public transportation is a key part of creating sustainable communities. It may include buses, street cars, subways, and light rail. Developing a transit system which incorporates multiple types of transit to address the majority of riders' needs will help to ensure that the system is accepted as a convenient way to travel. A good transit system not only reduces fuel consumption, carbon emissions and smog, but also helps to alleviate traffic congestion. Developing a high quality system for public transit is more feasible when it can be integrated into compact, high density urban areas where user frequency is high enough to generate adequate revenue.

Cycling
Cycling is an important form of public transportation due to its lack of environmental impact and the added health benefits of remaining physically active. One of the most effective methods of promoting cycling as a means of transportation is the regular upkeep of bicycle paths and lanes within the city, particularly in high-use areas. Bike share programs can also be an important tool to help to make cycling a feasible mode of transportation for many individuals. Bike shares are generally initiated by municipal governments and maintained by private companies. They work by providing centrally located bike racks where bikes can be rented by anyone with a credit card. Swiping the card at a rack releases a bike for use for a small fee. These programs can be successful provided that they receive sufficient funding and find ways to prevent theft.

Walking
Walking is also an important form of alternative transportation to promote as part of sustainable communities. Walking can be promoted by creating well-designed and well-maintained public pathways for pedestrian traffic. The main component of a pedestrian network is the city street network itself. Constructing and maintaining sidewalk spaces that facilitate the flow of pedestrian traffic encourages individuals to choose walking and cycling as an alternative to driving. Other parts of the pedestrian network include walking paths, as well as underground pedestrian tunnel systems, such as Toronto's PATH system.