How to merge shapefiles?

How to know if an interstate ramp has merge area or no merge area. Isn't it better for them to post signs?

• how to know if an interstate highway ramp has merge area or no merge area. Isn't it better for them to post signs like "no merge area. be alert". I had the bad luck of going through a ramp that connects to the interstate highway. Unfortunately that ramp did NOT have any merge area and there was no sign or symbol of "no merge area". Now their was also an impatient car behind me. I thought that I should stop to see if there is merge area or not. But the car behind me started giving me big horns. Due to those horn, I could not stop for barely a second and went on to interstate highway only to realize I was almost about to get run over by an 18 wheeler. As soon as I entered the interstate from that ramp (out of pressure from the car behind me that horned me), I came right in front of an 18 wheeler going 70 mph, just few feet behind me. He gave a very loud horn after loud horn. I panicked and climbed the curb, with half car on the lane and half on the curb. The 18 wheeler then managed to change lane and again gave angry horns. I could have been run over by 18 wheeler. There was no time to accelerate from 0 to 70 in 3 seconds. If the 18 wheeler did not change lane, I would have been history. And its all because of the car who gave me big horn on the ramp. That same car then himself waits before merging. Was that driver trying to get me killed?

• Answer:

  I agree. I have seen two on-ramps that were steeply uphill and just dumped the driver precipitously into the right lane of the freeway. One was on I-24 in California on the west end of the Caldecott tunnel, another is on a rural road onto I40 here near Flagstaff. In both cases few cars can manage more than 25 mph below the freeway speed limit before they are forced to merge. There really ought to be warnings. By the way, the driver behind you is rarely likely to know your business better than you are. You are the captain.