Horizontal Alignment
Horizontal alignment of a road includes horizontal curve and superelevation. These are discussed briefly in the following subsections.
Horizontal Curve
You might have observed that the roads are not always straight. Horizontal curves are provided to change the direction or alignment of a road giving due considerations to the comfort and safety of vehicles. However, each horizontal curve is designed considering speed, and it is dangerous to cross that speed limit. You need to respect the posted speed limit, if any, for your safety. Over speeding even on a straight road is unsafe and on a curve, it is unquestionably dangerous. The speed of the vehicle is your choice, and so is your safety on curves.
Superelevation
You need to know that on horizontal curves, a gradual slope is provided laterally by raising the outer edge of the pavement with respect to the inner edge. This is called superelevation, and it is provided for a scientific reason to enhance your comfort and safety. Speed is an important consideration guiding the design of curves and superelevation. So, you must respect the speed limit on curves. It is also pertinent for you to know that while negotiating a curve, the front wheels and rear wheels of the vehicle do not follow the same path which is called off-tracking. Although in most cases, an extra widening of the carriageway is provided on curves for this purpose, you need to keep in mind the off-tracking of the vehicle while negotiating a curve and crossing a vehicle from the opposite direction (on an undivided road with two-way traffic movements).