文档介绍：Shan Chen 1
3rd Urban Street Symposium
June 24-27, 2007 Seattle, Washington
Submission date: May 5, 2007
Word count: 2750+11 figures=2750+2750=5500
Figures: 11
Author’s name: Shan Chen
Affiliation: California Department of Transportation
Address: Caltrans, District 7, Office of Design C,
100 South Main Street, Los Angeles, CA 90012.
Phone number: (213)897-0396
Fax number: (213)897-0760
Email: schen_ca@
Shan Chen 2
Geometric Design of Interchange in Urban City
ABSTRACT
Rapid development in urban areas raises the demands for higher capacity, more efficient and
safer transportation systems while increasingly emphasizing limited environmental impact. Many
present geometric and operational characteristics of the transportation facilities constructed
decades ago cannot meet the current or anticipated future needs. The challenges facing the
designers are to improve functionality of transportation system and preserve environment
especially when it is located in a city with interchange configuration.
This paper presents the actual geometric solutions of a practical project involving multiple tasks
and substantial constrains in an environmental sensitive area. With defined and desired project
scopes, geometric designs of this project are optimized to provide best solutions while having
minimal environmental impact.
It shows that how three dimensional configuration and detailed geometric design are applied
using design flexibility to fit in an urban area surrounded by business, schools, churches, and
residential houses. It covers hook ramps geometry, the profile design of the overcrossing bridge,
highway widening and realigning, spiral pedestrian bridge design and special superelevation
handling for lane reduction in a area with substantial elevation differences and restriction. Sight
distances, design speeds, environment impact, safety, drainage and