What is a Parkway?
CAMPO defines a parkway as:
• Parkway (PKWY): Parkways are intended primarily for through vehicle traffic traveling at high speeds.� Through travel lanes are similar in characteristics to freeways, however, continuous frontage roads are not provided. Access is provided by grade-separated interchanges and ramps at major crossings. Whenever possible, landscape treatments and scenic easements are provided. Pedestrian and bicycle access is prohibited along the through travel lanes but may be provided through parallel facilities.

By this definition, Southwest Parkway is actually a misnomer since it has traffic lights. A better example of a parkway is MoPac between the river and 45th street. Below is another scene typical of parkways, showing a crossover for local access.
