Here, there are two types of accidents:
1. Due to poor visibility and road conditions
(due to these reasons people used to avoid it night)
2. Accidents due to increase of traffic on the narrow roads.
Now, even after markings , the number of accidents increased.
E says,
That means the people who used to avoid these roads started using it, especially at night. ..(here,there is a difference between poor visibility and total lack of visibility(i.e at night))
Thus as many people took that road at night.. there were more accidents due to lack of visibility and road conditions.
thanks.
Note:there is no mention of visibility of markings at "night".

















