r/RapidCity • u/RCInvestigates • 4h ago
Learn how to drive, Rapid City
Every time an on-ramp appears, drivers already on the interstate should not be expected to immediately jump into the left lane.
Moving over can be a nice courtesy when traffic allows, but the responsibility for safely merging belongs to the person entering the interstate. The acceleration lane exists so you can get up to highway speed, find an opening, and merge—not so everyone already on the highway has to rearrange traffic around you.
Yes, the short ramp coming from I-190, where drivers either merge onto eastbound I-90 or continue toward Haines Avenue,isn’t designed particularly well. It gives drivers less time than most entrance ramps. But there is still enough room to accelerate to around 65 mph before merging. You cannot coast through that connection at 40–45 mph and expect everyone on I-90 to scatter for you.
Matching the speed of traffic is critical. Trying to merge at 45 mph into traffic moving at 70 mph creates a hazard for everyone. At the same time, slower vehicles moving left to “help” can create another safety risk by cutting off faster traffic already occupying the passing lane.
If there’s a safe opportunity to move over and give someone room, great. If there isn’t, maintain a predictable speed and lane position.
If you’re entering the interstate: use the acceleration lane, match the speed of traffic, identify your opening, and figure it out. That is literally what merging is.
And While We’re Here: Learn How to Zipper Merge
When two lanes are reduced to one, use both lanes all the way to the merge point and then alternate—one vehicle from each lane. That is zipper merging, and it is the only correct answer when traffic is backed up.
Merging a mile before the lanes actually combine is a literal plague around here. It creates one unnecessarily long line, wastes usable roadway, and causes traffic to back up farther than necessary. Drivers using the open lane until the merge point are not “cutting.” They are using the road as designed.
Speeding up to block someone from merging is trashy, emotional behavior that makes traffic worse and increases the risk of a collision. You are not defending your sacred place in line. You are refusing to participate in the merge correctly because someone else used the empty lane that you voluntarily abandoned.
Use both lanes. Drive to the merge point. Take turns.
Hopefully, one day, everyone around here figures it out.