Abstract
In rt:oent yeara, the Califoxnia Division of Ilighwaya deaigna-ted tkhiaknesaea of portland oercent concrete pavement equal ttthe deptha of atandard aide forms. fhe aelection of thicknesaof the pavement and the underlying amen t.treated lager wasbaaed on California"s traffic Index whioh was developed foruse in flexible pavement deaigno Heoauae (raffia Index is oom;puted Erom all pr:dicted truck axle loadinga, ita is not ne-ceasarily valid tor rigid pavement designco