Exit-only lane for an unfamiliar destination
You are driving east on a Missouri interstate at 9:10 p.m. in an unfamiliar area. You want Route 63 South toward Jefferson City and a gas station. An advance guide sign reads 'Exit 112 - Route 63 South / Jefferson City - 1 MILE.' A second sign over the right lane reads 'EXIT ONLY' with a downward arrow. You are currently in the left of the two through lanes, 0.3 mile before the exit. Traffic is heavy and the left lane is moving about 10 mph faster. Your fuel gauge is below one-quarter. The exit ramp has a gas station sign at the top. The gore area between the exit ramp and the through lanes begins in about 800 feet. You are not familiar with the next exit.
1. Which lane should you be in, and when should you move?
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You should be in the right lane and prepared to exit. The advance sign gives you a mile of notice; the 'EXIT ONLY' sign over the right lane confirms that the right lane leads to Exit 112. At 0.3 mile with heavy traffic, waiting until the last 100 feet increases the chance of a sudden merge or a missed exit. Signal early, check the mirror and blind spot, and move right as soon as there is a safe gap. Do not speed up simply because the left lane is moving faster; the correct lane is determined by the destination, not by the faster traffic. If traffic will not allow a safe lane change, accept the miss and take the next exit rather than forcing a late cut across the gore.
2. The left lane is moving faster. Can you use the exit-only lane to pass traffic and then merge left before the gore?
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No. The right lane is marked 'EXIT ONLY,' so entering it commits you to the exit. Using an exit-only lane as a passing lane is unsafe and defeats the purpose of the sign: drivers in the through lane may not expect a vehicle to accelerate past on the right and then cut back left. The gore area is a striped separation zone, not a merge lane; crossing it is not a normal lane change. With heavy traffic and only 800 feet before the gore, the risk of a sideswipe or a late swerve is high. Stay in the correct lane for your destination, or if you miss the exit, continue to the next interchange and turn around legally.
3. At the top of the ramp you realize you wanted Route 63 North, not South. What should you do?
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Do not stop at the top of the ramp or back down it. The guide sign and the exit-only lane have already committed you to Exit 112; once you are on the ramp, the safe course is to continue, find a legal place to turn around or re-enter the interstate, and correct the direction there. Read the destination and direction on the advance sign before the exit, not after. If the ramp splits, follow the sign for the direction you can legally take and use the next interchange rather than making an abrupt lane change near the gore. The gas station can still be used, but the route correction should happen on local roads or at the next exit.