The area between the acceleration lane and the roadway that may not be crossed is known as the .

The answer is the "gore area". This part of the lane merging across from a road traffic this is placed to protect two merging parts of the traffic flow.

gore area (driversed.com)

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.