On major highways, bridge deck replacement often involves a diversion of traffic by shifting the travel lane adjacent to the repaired roadway. Thus, any traffic vibration or differential deflection, induced transversely due to truck traffic in the adjacent lanes, can affect the fresh concrete. Although there is very little evidence that traffic vibration in the adjacent lanes has affected the serviceability of concrete bridges in the past, more recently there have been some concerns about pouring high-performance concrete (HPC) in adjacent lanes because transverse cracking has been observed on newly repaired bridge decks. This paper examines the impact of traffic diversions and deflections that are induced transversely by truck traffic in adjacent lanes on the serviceability of bridge decks. In addition to field monitoring and laboratory testing, finite element analyses were used to simulate various bridge deck systems, traffic patterns, and truck loads to determine their effects on the serviceability of bridge decks. Results indicated that traffic loads and patterns can adversely affect the serviceability of concrete bridge decks. The results revealed that specific modifications to construction procedures and materials can significantly reduce the degree of transverse cracking in bridge decks.