Just because you’re getting off the highway one exit after you got on, that doesn’t mean you’re exempt from the requirement to merge properly. If you’re forcing your way into the flow of traffic because you haven’t bothered to match others’ speed, you’re breaking the law as surely if you’re going 25mph slower as if you’re going 10mph faster. You’re also endangering other motorists more, because the danger is proportional to the difference in speed and not the speed itself. Do it right or stay off the highway for that half-mile.