A field full scale flexible road is constructed and the effects of geotextile reinforcement in paved road are tested by measuring the occurred rutting. The effect of different numbers and positions of geotextile reinforcement using seven road sections are evaluated and compared with unreinforced pavement section. It is found that a maximum reduction of rut depth is 96% when using three reinforcement layers at three different road layers interfaces, and a minimum reduction is 52% when using one reinforcement layer at interface I ( between wearing and binder layers) under the effect of maximum load cycles of 10000. The minimum Traffic Benefit Ratio (TBR= ratio between load cycles on a reinforced section to that of unreinforced section for the same rut depth) is found to be 4 when using one reinforcement layer in the interfaces I , and extremely large values for other reinforcement cases. Once, the above values appear how the service life of the paved road is increased by using geotextile reinforcement.
The cost-benefit analysis is also adopted in this research and found that by using one reinforcement layer the road cost is increased by only 14% resulting in increment value of TBR to 4 (this means that the road life is doubled 4 times if all other circumstances are fixed). This is a minimum case benefit when comparing it with all other cases; it is found that TBR values are exaggerated when different numbers and positions of geotextile reinforcement layers are used.