The first sign has to be at least 300 feet before the system and additional signs shall be more than 300 feet before the system.
Dhererka qulqulka ugu weyn waa in uu ahaado ugu yaraan 30 cm, sidoo kale, nidaamka asaasiga ahi waa in lagu muujiyo tiro badan oo xididada dhinacooda ka baxsan.