What happens to tack if traffic is allowed on it before it breaks?

When traffic is allowed on tack before it has adequately broken, the tack becomes disturbed and can result in a non-uniform application. The primary purpose of tack is to create a strong bond between layers of asphalt; however, if traffic is introduced too soon, it compromises the integrity of that bond.

The movement and weight of vehicles cause the tack to be spread unevenly, which can lead to areas of insufficient adhesion. Consequently, this non-uniform distribution renders the tack ineffective, preventing the asphalt layers from properly bonding as intended. Proper timing is crucial for the performance of the asphalt pavement, and allowing traffic too early interrupts this critical process.

In contrast, the other choices do not correctly encompass the primary effect of premature traffic on tack. While some may imply potential consequences, they do not directly address how it affects the bond's effectiveness as clearly as non-uniformity does.