In geometric design of highways, identify the incorrect statement about super-elevation e and its functional dependence on key variables.

Introduction / Context:
Super-elevation is the transverse slope provided on horizontal curves to counteract centrifugal effects and improve vehicle stability. For design speed V and curve radius R, the basic relationship e + f = V^2 / (g * R) (in consistent units) shows how e depends on speed, gravity, and curvature. This question asks which statement about e is incorrect.

Given Data / Assumptions:

• e is provided as a ratio or percentage of cross slope.
• V is the design speed, R is the radius of the horizontal curve, g is acceleration due to gravity.
• Pavement width does not enter the fundamental e–V–R–g relation.

Concept / Approach:
The fundamental dependence is e ∝ V^2 and e ∝ 1/R, with gravity g in the denominator. Width of pavement affects lane configuration and runoff length but does not directly appear in the governing relation for required e for a given V and R.

Step-by-Step Solution:
Recognize from e + f = V^2/(gR) that e increases with V and decreases with R and g.Note that pavement width W does not appear in the formula; thus, any claim of direct proportionality to W is incorrect.Conclude that the incorrect statement is the one tying e directly to pavement width.

Verification / Alternative check:
Design standards specify super-elevation independently of pavement width; width influences other features like shoulder cross-fall and runoff length but not the basic e calculation.

Why Other Options Are Wrong:

• e increases with speed: qualitatively true because e ∝ V^2.
• e is inversely proportional to g: correct since g appears in the denominator.
• e is inversely proportional to R: correct; tighter curves (smaller R) need larger e.

Common Pitfalls:

• Equating construction practicalities (wider pavements ease runoff) with the core e formula.
• Confusing design speed V with operating speed distribution.

Final Answer:
Super-elevation is directly proportional to the width of the pavement.