Summary: | The Intermediate Highway Design Skills (IHDS) Course incorporates the 2009 edition of Design Manual Part 2 that conforms closely to the 2004 Edition of the American Association of State Highway and Transportation Officials (AASHTO) Policy on Geometric Design of Highways and Streets, also known as the AASHTO Green Book. The IHDS course includes a review of the basic design principles taught in the Basic Highway Design Skills Course, intermediate concepts for Traffic, coordinate geometry, surveying, horizontal alignment and superelevation, vertical alignment, and at-grade intersections.
|
Learning Outcomes: | –Review PENNDOT’s hierarchy of highway functional classifications, and how various parameters, including design speed, design vehicles, and design criteria, influence the highway design process.
–Review the design criteria for Resurfacing, Restoration, and Rehabilitation (3R) projects as provided in Design Manual Part 2, Chapter 1.
–Given a rural freeway’s design speed, Average Annual Daily Traffic (AADT) volume, Peak Hour Factor (PHF), typical section, heavy vehicle percentages, and geometric data, be able to determine the following:
•K-Factor
•Heavy vehicle adjustment factor
•Density in pcpmpl
•Free Flow Speed in mph
•Level of Service
–Be able to determine the coordinates of:
•A point in line with two known points
•A point on a line given the coordinates of another point offset
from the line
•The intersection point of two lines
–Determine the latitudes and departures of the courses of a closed traverse, and its angular error of closure using the methods presented in the workbook.
–Apply the Compass Rule to determine the linear error of closure and ratio of precision of a closed traverse.
–Be able to perform horizontal alignment design activities including circular curve layout, spiral curve selection, horizontal sight distance calculation, and traveled way determination.
–Be able to design superelevation transitions for various combinations of highway functional classification, horizontal alignment, design speed, and maximum superelevation rate.
–Given an upgrade and the entering speed of a typical heavy truck, calculate:
•The truck’s speed at various points along the upgrade
•The critical length of grade
–Given vertical alignment, use the tables and graphs in the workbook to calculate the required length of Crest Vertical Curve and/or Sag Vertical Curve for various conditions, including:
•Stopping Sight Distance
•Passing Sight Distance
•Headlight Sight Distance
–Given a fixed point along a vertical alignment, calculate the length of the symmetrical vertical curve that passes through the point.
–Given a highway intersection and design vehicle type, be able to develop the minimum edge-of-traveled-way design for a turning road using a:
•Simple curve radius
•Simple curve radius with taper
•Three-centered compound curve.
–Given a variety of intersection control conditions, maneuvers, and roadway design speeds, be able to determine:
•The required intersection sight distance
•Time gap for minor road to major road entry
–Gain familiarity with Context Sensitive Solutions (CSS) by examining the following components, Community Context, Placemaking, Flexible Design, and Public Involvement.
–Review sidewalk design criteria as outlined in Design Manual Part 2 (DM-2), Chapter 6 and other elements affecting the geometric design of highways, as presented in the AASHTO Green Book and DM-2, Chapter 2.
|