Should i give my child a phone?

My son is 6 and starting Elementary school in September.. and i have this great fear for him on the school bus. I'm always seeing stories of drivers forgetting kids on the bus or dropping them off at the wrong stop. Am i being over protective? I saw an ad for the mommy phones were the phone only has 4 buttons and I would preset all the numbers he could call.. and not to mention I could GPS his location if anything.. I need some insight please. Thanks a bunch