8.4.1 General Design Considerations
Freeways in urban contexts are typically classified as depressed, elevated, ground-level, or a combination thereof. These freeway types are used as appropriate for the surrounding areas or conditions.
Freeways in urban contexts can carry high traffic volumes and may have any number of through-traffic lanes in one direction if the minimum level of service requirements are met. However, it is commonly accepted that freeways become less efficient at widths greater than four lanes in each direction. When more than four lanes in each direction are needed, consideration should be given to implementing a special freeway design. For special freeway designs, see
.
Medians on freeways in urban contexts should be a minimum of 12-ft for a four-lane freeway and 24-ft for a freeway with six or more lanes, and preferably 26-ft with heavy truck traffic to provide a wider shoulder.
Freeways in the urban context typically do not require median crossovers.