US Driving - pulling onto a busy highway using on/off ramp

If you are moving at the flow of traffic trying to merge, you are doing your part.

The other guy was stuck in traffic going the same 10mph. He was hoping the weave lane would be wide open so he could use it to overtake main road traffic and speed to the next exit (or even merge back in near the end, the sneak!) He was sore because he couldn't - but them's the breaks. His crazed overtake on the shoulder was illegal and would have gotten him a $200 ticket if a cop had seen him.

Even if you weren't there, the exit lane isn't really intended for overtaking while exiting. Not least this would be passing on the right, which is illegal many places when done as an intentional act. You can kind of get away with it if you really are exiting.

Now there is discussion that merging at the last possible minute may be better... but that discussion may not apply to a weave lane since you'd be plugging up the works for all the "exit"ers.

My driving instructor explicitly told me that, when one doesn't succeed in weaving from the acceleration lane onto the outermost lane, there is a difference between what one should do in theory and what one should do in practice. This applies to the situation where the enter lane ends and does not continue into an exit lane.

In theory, he said, one is supposed to stop at the end of the enter lane. This is very dangerous unless traffic on the motorway is very slow anyway, because other traffic trying to enter will try to go as fast as traffic on the innermost lane, perhaps faster in order to try to enter.

In practice, he said, the wisest thing to do in this case is to enter the emergency lane. This is prohibited, because it does not count as an emergency.

Faced with the choice between very dangerous and prohibited, I would choose the prohibited alternative. Fortunately, I've never experienced the situation in which I failed to merge with fast-flowing traffic, but I don't drive much.

But in your case the enter lane becomes and exit lane, so then you can safely exit the motorway and try again. Do not stop unless the highway is experiencing slow-moving/stopping traffic already. The on/off ramp is part of the motorway and stopping when others are doing 120 km/h (75 mph) is very dangerous.

The general consideration of merging onto any road, be it a highway or a regular street, is that if there are on-coming vehicles -> you have to let them pass. Your letting them pass means that you should not disrupt the traffic pattern i.e. making them slow down, change lanes etc. Your letting them pass may need you to simply slow down your vehicle or to bring it to a complete stop.

The Colorado DMV states that:

Merging: You must yield to all vehicles on that roadway. Do not merge if another vehicle must slow down for you.

Furthermore about high:

High speed roadways generally have acceleration ramps to give you time to build up your speed. When entering a freeway from an on-ramp try to increase your speed to match that of the freeway traffic. Do not merge into traffic until the solid white line has ended. Do not stop in the acceleration lane unless absolutely necessary. Remember, you must yield the rightof-way to the traffic already on the freeway.

• Adjust to freeway speed in the acceleration lane.
• Do not cross the solid white line.
• Signal and move carefully into the freeway lane.

And yes that the other driver did was wrong. Also in some states it's illegal to drive on the shoulder/emergency lane (i.e. lane to the right of the last lane) unless speficially mentioned what times of the day you can use them.

EDIT: Having a look at your picture gives more clarity. Usually interstates have a couple of miles distance between an entrance and an exit and people usually tend to merge way before the exit approaches. But in a situation where both of these points are so close, you might notice that once the merge lane starts the solid white line on your left will turn into a dashed line for merging traffic to cross over. After that it would go solid again for a short distance and then again dashed for exiting traffic to cross over. So the rule would be to merge or stop of you cannot merge before the dashed line turns solid.

If the line stays dashed the whole way, then it would create confusions during rush-hours/jams etc. and then you can use your best judgements only. I would stop a quarter mile before the exit with my signal on and wait for an opportunity to merge or some on car's front light flash as an indication that I can come infront of him/her.

It doesn't sound like you did anything wrong. If you reach the end without being able to merge then you should take the exit. It shouldn't be too hard to come back to the same on ramp and try again with most interchange designs. Below is a real example, northbound on M23/37B entering Ann Arbor, MI one takes the exit/entrance shown below. This is one that stands out in my memory as having a rather short distance to merge/exit while being quite busy, and the exit ramp radius is quite tight so many unsuspecting drivers end up off the road in winter... The situation is the same going south on M23/37A, I'm just more familiar with the other way. What the other car did is almost certainly illegal, falling under reckless driving if nothing else, in most (all?) states using the shoulder that way is illegal. If there is an area with only shoulder between the on and off ramps then you should instead wait to merge, but here where on and off are not separated you should not stop. The other car should have waited behind you, regardless of whether you stopped or continued. Road rage is a serious issue in the US.