That car should not be overheating at 100 K/hr (62.1 Miles/hr). There should be enough airflow at that speed to make the fan unnecessary, so I am discounting fan failure. However, at city street speeds on a summer day, the electric fan is needed, and It will overheat if this is not working. A failed temperture switch/sensor in the fan circuit is a common failure for engines more than 4 years old.

Since you are reporting overheat at highway speeds, I would look at anything that reduces cooling capacity like a plugged radiator, trash collected in front of the radiator, a thermostat that doesn't open fully, collasping radiator hoses (the bottom one in particular), etc.

Jem is right on with his impression of how to deal with this. It is simply a coolant flow, or heat transfer issue.

One other possibility is water pump impeller failure/erosion.

Using a scan tool to watch the engine temperature as it changes through various engine loads and speeds one can often determine if it has an airflow (heat transfer) problem or if it is a coolant speed issue. I use my infrared thermometer to measure surface temperatures of the radiator both with the coolant fans running and off to try and measure for cold spots which would be signs of restrictions in the radiator.

Suprisingly, waterpumps that have a plastic impeller that has fallen completely off will often times still move enough coolant to cool an engine at idle or under a light engine load. The temperature may be higher than "normal" which would be 198f-207f while driving steady speed on the road. With an impeller failure something like 205f-215f might be seen, and almost as soon as you pull over, or especially while coasting you will see a drop in the temperature . This is an indication that if the coolant moves quick enough in relationship to the heat the engine is generating then the cooling system would perform as expected.

Unfortunately with few exceptions, if a failed waterpump impeller is suspected the only way to check it is to remove the pump, and then you should just plan to replace it while it's off anyway. Of course with a Neon, that usually means a timing belt, idler pulleys, and updated tensioner and rear cover if it has not already had the up-grade. Failure to repair this will of course result in a blown headgasket and that could be just about considered fatal to a 95 Neon cost wise.

Thanks for all the input guys. Good info. Well, your not going to believe this. I've got it fixed. Here is one for the books. I have my own ideas on this, anyone else? After
looking at it found the engine ground from the battery was burned off at the block. Yes the engine light was on but never pulled the code, didn't have the chance. This guy would push the car down the road, hop in and dump the clutch to get it started when hot. This is the same guy that connected a house hold light switch to the started
solinoid to start his 86 taurus because he was too lazy to
replace the ignition switch. Anyway it starts fine on it's own even when hot. Doesn't over heat anymore. I think the electrical system went to limp mode because before i fixed it the timing was way too high. It is now normal. If i had the chance to put the scanner on it i'll bet everything would show low voltage. Yes the engine light is off. Went off by itself. I'm sure i haven't seen the last of this thing. I'll probably end up owning it. Thanks again guys.
I really appreciate all the help. I really don't like asking for help because i want to figure it out for myself
but you got to do what you have to do. Thanks again.