Option 1 -> rule out means to eliminate or exclude something, which is the opposite of what's needed here.
Option 2 -> rely on means to depend on or trust something; the government had to depend on new safety measures to address the problem.
Option 3 -> pull up means to stop or halt (usually vehicles) or to reprimand someone, which doesn't fit this context.
Option 4 -> run into means to encounter unexpectedly or collide with something, which is inappropriate here.
Hence, Option 2: rely on -> The government needed to depend on new safety measures as a solution to control rising road accidents -> correct