Message from the Director: Wait for it

Wait for it

In pavement research, our drive to innovate often pushes us to seek quick answers. When new materials, construction methods, or design concepts are introduced, it is natural to want quick feedback on whether the change will improve performance. Laboratory tests, short-term monitoring, and early performance indicators can provide useful insights. However, the true test of any innovation lies in how it performs under traffic and environmental conditions over time. In other words, when it comes to field experiments, we must be willing to “wait for it”.

Field experiments are indispensable for evaluating new ideas in asphalt pavements, allowing us to see how innovations perform in real-world conditions. But too often, test sections aren’t observed long enough. A few years of monitoring rarely reveals the full effects, and without sufficient time, we risk drawing premature conclusions — either overstating benefits or dismissing approaches that could ultimately prove valuable. I was reminded of the lost opportunity of failing to follow through with long-term field evaluations of test sections in the literature review of longitudinal joint studies conducted in the 1990s and early 2000s (see related article on p.4). At least six state DOTs built well-documented field projects with numerous joint treatments, but none of those projects were evaluated for more than six years, and therefore, we don’t know which treatment was the best.

Long-term monitoring is vital given the complexity of asphalt pavement performance. Aging, traffic, climate, materials, and construction all interact over time, and only extended observation can reveal whether performance differences stem from the test variable or short-term noise.

At NCAT, we are committed to the principle that meaningful research often requires a long view. Our Test Track provides a unique opportunity to accelerate the accumulation of traffic loads, but even with accelerated testing, we recognize the need for extended evaluation. Likewise, the MnROAD facility, owned and operated by the Minnesota Department of Transportation, has demonstrated the tremendous value of monitoring pavement test sections over decades in a northern climate.

The message here is simple: good science takes time. In pavement research, time is not a luxury but a necessity. If we want to provide agencies and industry with reliable, conclusive evidence about what works and what does not, we must be willing to wait. True advances in pavement design, materials selection, and maintenance strategies come from studies that capture the full story — not just the opening chapters.

As we look ahead, NCAT will continue to emphasize the importance of long-term monitoring in our research partnerships. By committing to follow test sections until they reach end-of-service thresholds, we can ensure that our recommendations are based on solid, conclusive evidence. In the end, the message for all of us is clear: when it comes to pavement research, the payoff comes to those who “wait for it”.