Safe and Complete Streets Act of 2008 - Requires each state to have in effect within two years a law, or each state department of transportation or metropolitan planning organization an explicit policy statement, that requires all federally-funded transportation projects to accommodate the safety and convenience of all users in accordance with certain complete streets principles.
Defines "complete streets principles" as federal, state, local, or regional level transportation laws, policies, or principles which ensure that the safety and convenience of all users of a transportation system, including pedestrians, bicyclists, and transit users as well as children, older people, motorists, and those with disabilities, are accommodated in all phases of project planning and development.
Allows such law or policy to make exemptions from such principles only if: (1) affected roadways prohibit specified users by law from using them, the cost of a compliance project would be excessively disproportionate to the need, or the population and employment densities or level of transit service around a roadway is low enough that there is no need to implement such principles; and (2) all project-specific exemptions are properly approved.
Requires states to ensure that every agency responsible for a project within an approved transportation improvement program reviews and certifies that the project incorporates complete streets principles.
Requires the U.S. Access Board to issue final standards for accessibility of new construction and alterations of pedestrian facilities for public rights-of-way.