What is required on joints when adjacent travel lanes differ in elevation?

When adjacent travel lanes differ in elevation, utilizing tapers is essential for creating a smooth transition between the two surfaces. Tapers, which are gradual slopes or angled transitions, help to mitigate abrupt changes in height that could create safety hazards or discomfort for vehicles moving from one lane to another. They ensure that vehicles can move seamlessly between lanes without a sudden drop or rise, reducing the risk of accidents and enhancing driver comfort.

In this context, having a tapered joint also assists in the structural integrity of the pavement, as it helps distribute the stresses that result from traffic loads more evenly. This is crucial for pavement longevity and performance, as abrupt changes can lead to distress and deterioration over time.

The other choices either fail to address the need for maintaining a smooth driving surface or do not provide an effective solution to the challenges posed by differing elevations in adjacent lanes.