What's so hard about giving a signal?

Okay, today is installment #2 in the "Random Things That Bug Me" series. This series will continue, with no preset schedule, throughout the life of this blog.

I'm sure all of you have been in this situation before. Or at least you have if you've experienced Pennsylvania and our many highways with exceedingly short entrance ramps. As you come up the entrance ramp, there's no space immediately available for you to merge into. So, you stop on the ramp and wait, leaving yourself enough room to get up to speed when you finally get an open spot. You're waiting there, looking for your gap. You see a very nice opening after this one last car that is coming that will suit you fine. So, you start accelerating down the ramp, keeping that last car and opening in your view, waiting for the car to go past you so you can pull out onto the highway.

Suddenly, you notice that gap is getting smaller, and that last car hasn't gone past you nearly as quickly as you would have expected. You realize that the last car has been slowing down to let you in. And course, you realize this just about the time it becomes too late for you to pull out in front of them, unless that last car comes to an almost complete stop, which they almost inevitably do. At no point during this entire sequence did they do anything to signal to you that they were going to let you in. So now, in the best case, you pull in front of a stopped car and traffic is momentarily screwed up, and in the worst case, they still end up driving by you and now that wonderful gap behind them no longer exists, and you're still waiting to merge, only further up the ramp and with less room to get up to speed on the next attempt. (Ah, the glory of PA highways)

And so I have to ask of this representative person with the misguided attempt at being a Good Samaritan, what's so hard about giving a signal? I'm in front of you, so I can't see your brake lights, and it's really hard to detect the deceleration of another car when viewing it through the rear view mirror. And furthermore, couldn't you have looked in YOUR rear view mirror before all of this and realized that had you just continued by at your standard speed, I could have merged in right behind you without any inconvenience to you, me, or anyone else we share the road with. I appreciate the thought, I really do. In this me-first society, it is refreshing to see someone being so selfless in this situation. But seriously, just take my advice and you'll save us both a lot of headaches next time.