Load transfer at rigid pavement joints is a complex mechanism that can vary with concrete pavement temperature, age, moisture content, construction quality, magnitude and repetition of load, and type of joint. The FAA design procedure assumes 25 percent of the load applied to an edge of a slab is transferred at the joint to an adjacent unloaded slab. This effectively reduces the edge stress in the loaded slab by 25 percent compared to a free edge condition allowing fbr a reduced slab thickness. If the load transfer assumption is violated through a degradation of the joint system, the pavement life can be significantly reduced. The purpose of this study was to evaluate the load transfer effectiveness of several concrete pavement joint types by using nondestructive testing techniques. Several joint types and conditions that affect the efficiency of the joints were considered. Nondestructive field testing was conducted at four U.S. airports with a heavyweight deflectometer (HWD). Joint load transfer was found to be stochastic and not be adequately described by a single deterministic value. Probability distributions for the joint types and conditions were proposed. Based upon these probability distribution flinctions, the likelihood of observing mean values of load transfer less than 25 percent ranges from 60 to 100 percent, depending on the joint type and conditions. (MM).