RESEARCH NEEDS for Construction TAG

RESEARCH NEEDS FOR Construction TAG

EFFECTIVE/UPDATED 8/15/17

ISSUE: Optimizing the Benefits of Smoother Roads against the Increased Costs to Build Them

SUMMARY OF PROBLEM: Roads built smoother initially last longer; that is a fact of the performance curve mathematics. However, incremental improvements past a certain point drive costs of construction up as more sophisticated machine controls have to be acquired and more highly skilled finishers that can "see" roughness have to be employed behind the paver to ensure there are no bumps or dips. Both of these items cost money to the Department through increased bid costs which may or may not be justified.

Since smoothness specifications were actively pursued by industry in the late 70's and early 80's roadway construction has continuously improved to where a good ride is the norm, not the exception. However, specifications on smoothness continue to be tightened down over time to the point that the question has to be raised, "How smooth is smooth enough?"

The answer to that question should be not just be a spec that gets applied everywhere as frequently happens with the current specification implementation. The specification should match the needs. State highways with many intersections, adjacent business entrances, and gap requirements do not need to be built to the same standards as traffic is not usually full-highway speed free-flow such as a rural Interstate section. The specifications used should match the need; sometimes they do not. However, the bid price will always reflect the demands imposed by the specification rather than the actual need.

The subject of "how smooth is smooth enough" needs to be investigated and perhaps specifications changed to rationally developed numbers that optimize the pavement smoothness obtained and performance extended against the increased cost of building those sections. The specifications should also reflect the application for which they are intended whether it is a high-volume expressway, or a subdivision city street.

DESIRED RESULTS/OUTCOME: Rationally developed smoothness specifications that optimize quality and performance against the increased cost to achieve levels of roughness that are not even detectable to the highway user. Such specifications will ensure that the Department does not pay excessively for incentives that do not matter, yet ensures a long-life pavement