Analysis tools may be classified as either deterministic or stochastic. Stochastic tools account for randomness, while deterministic tools do not. Because of this, stochastic tools more accurately represent variability present in a traffic network (e.g., varying speeds among drivers, varying reaction times, and varying acceleration and deceleration rates). Microsimulation-based (microscopic) tools are typically stochastic, while the HCM-based and spreadsheet-based tools are deterministic.