2oldman wrote:
Samanthahhi wrote:
This is what makes me think there is little to no cell phone coverage:
That's the 4g data coverage map. If you stay on interstates, they almost always have voice coverage. I don't know what roads you'll be on.
Statements like this make me wonder where people actually travel. Cell phones will work in most but not ALL areas and that is why the OP asked for help and not comments demonstrating the posters ignorance.
We often encounter stretches of highway where we go a hundred miles or more with no cell reception and this has occurred in California along I-5 and Hwy 101 and in Montana and Idaho and Utah and Arizona and New Mexico. Cell towers require electrical power and where there is no electrical power there are no towers and no cell service. Check the online cell tower location maps and it is easy to see this limitation. We don't get cell reception at our house and there is a Verizon tower located less than 2 miles away.
Cell tower range is 4 miles and in very flat country might be up to 10 miles but that is rare. The limitation is the outgoing signal of the cell phone that has to make it to the tower. Everyone has been on calls where the person with the cell phone can hear you (they get the tower to the phone signal) but you cannot hear them as the cell phone's signal is not making it to the tower.
The best public use devices that do not rely on cell towers are the GMRS radios. All hand held radios have a very limited range as they are limited in terms of the antenna that is provided (and no external antenna or booster is allowed by law) and they have very limited signal output which is designed to protect the user as these radios will be transmitting with the radio held against the users' heads.
The manufacturers' claims about distance and signal strength cannot be trusted. They often state power levels that are 10x what they have actually tested and filed with the FCC. Read the reviews by owners of the FRS and GMRS hand held radios and you will find frequent complaints about lack of range.
Regardless of what you decide to use for communications I would still have a fallback to planned meeting places and times to hook up a couple times during the day to do a status check.