To obtain a portable instrument for measuring the rutted depth in a road which can be assembled and contained conveniently by bonding a thin string made of synthetic fibers or steel to the opposite ends of a resilient telescopic pipe made of metal or synthetic resin.

A resilient telescopic pipe 1 made of metal or synthetic resin is contracted to such a size as can be grasped with a hand and comprises pipes 1b-1g extending sequentially from a base part pipe 1a while decreasing the diameter gradually. A thin string 2 made of synthetic fibers or steel is bonded to the base end 4 of the base part pipe 1a and the tip 3 of the forward end pipe 1g. When the opposite ends of the pipe 1 are secured under fully stretched state, the pipe 1 is bowed and the thin string 2 is secured to provide a base line for measurement thus facilitating accurate measurement of the rutted depth. When the pipe 1 is contracted and the thin string 2 is wound up tightly around a hook 5 with a winder, the pipe 1 can be carried easily using a portable hook 7.