When a lane is ending and merging with another lane, the car that has the right of way is the car in the through lane or the lane that is not ending. The drivers and the lane that is closing should yield to the drivers and the through lane when trying to merge and should merge as soon as it is safe for them to do. So. Speeding between cars to get ahead is often unsafe but doing so at a merge is even riskier. Courtesy is the best rule of thumb. Drivers in the ending lane should use their turn signal when preparing to merge and drivers in the through lane should allow space for merging drivers to change lanes.