| 摘要 |
PROBLEM TO BE SOLVED: To provide a useful U-shaped drainage ditch so that a traffic sign can be installed upright near to the shoulder without traffic hindrance by simple construction such as replacement of a par of the U-shaped drainage ditch in its installation place in newly installing a road sign along a road. SOLUTION: A pole foundation part 6a for fixing a pole 4a of a traffic sign 4 is integrally formed rather closer to the shoulder of the road, a pole supporting pipe 6c is buried therein, a U-shaped groove 6b having a width and a height determined according to JIS standard (JIS A5305) is formed bypassing the pole foundation part on the outside thereof. The peripheral area of the pole foundation part and the U-shaped groove is enclosed with a reinforcement bar 6d. Thus, the drainage ditch is formed by such concrete cast product. In the case of newly installing a road sign along the road, only one of the existing U-shaped drainage ditches (standard product) laid in its installation place is replaced by the U-shaped drainage ditch 6 of the invention, and then the pole 4a of the road sign 4 is fixed up right in the pole foundation part. |
