Terminology of longitudinal slope on highways If the elevations along a road increase in the direction of travel, the longitudinal slope is called:

Introduction / Context:
Road longitudinal profiles are described using grades. Positive grades climb with chainage; negative grades descend. Clear terminology assists in drainage and capacity calculations.

Given Data / Assumptions:

• Elevation increases with distance along the alignment.
• Direction of travel coincides with increasing chainage.

Concept / Approach:
A “grade” is the longitudinal slope, expressed as a percentage or 1 in S. When the roadway rises in the travel direction, it is a positive grade; when it falls, it is a negative grade.

Step-by-Step Solution:

Verification / Alternative check:
Design drawings typically annotate +g for upgrades and −g for downgrades; drainage inlets and climbing lane needs are based on these signs.

Why Other Options Are Wrong:
“Gradient/grade” are generic terms; “negative grade” is the opposite case.

Common Pitfalls:
Mixing sign conventions when local coordinates are reversed; not distinguishing algebraic sum for vertical curves.

Final Answer:
positive grade