Entering Sight Distance (ESD) 1
Entering Sight Distance (ESD) 1 : The sight distance required for minor road drivers to enter or to cross a major road such that traffic on the major road is unimpeded. This is based on the worst case, usually being a left or right turn manoeuvre. entrained air (concrete) Bubbles of air in concrete, the purpose of which is to increase its resistance to frost and salt