A factorial analysis of peak period bus journey times in Dublin

A roadside peak period survey of four Dublin bus routes was designed and executed within the framework of a controlled experimental design. Bus speeds, while not varying significantly from route to route, are shown to follow a characteristic U‐shaped trend as departure times advance during both the morning and evening peaks. Bus headway times increase linearly during the morning peak. Distinct patterns of journey times and speeds emerged for different days of the week. The data confirmed that Friday evening is Dublin's worst traffic period, with speeds almost twenty percent slower than on Wednesday, the fastest day.