And once you have that, add this patch to your uniform, just to make it official:
http://cgi.ebay.com/9999wa-Wanker-iron-on-...7QQcmdZViewItem
Heck, buy 2 and you can put one on your jump bag, too!
I would take it a step further and test everyone on the squad on a regular basis. Having tenure on a squad does not ensure any level of competence and testing everyone eliminates any accusations of finger pointing or favoritism.
It may turn out some of the new people have stronger skill sets than some incumbents.
If testing exposes members needing training, meet with them one-on-one to set up necessary training and follow up to make sure it is completed and re-test. Handled properly (no public browbeatings), no one should have any issues with it.
I agree that GPS navigation is a nice tool, but it's not perfect. Our service has GPS navigation units in each rig. We've found that at times directions are spot-on. There are other times that directions are wrong or the address isn't found. There's always the possibility of user error, too.
You should do some in-depth testing to see how reliable it is in your area and use the GPS as a backup until you're very comfortable with it's degree of accuracy.
I own a Nuvi 350 and recently entered my parents address into it (they live in a small town). The directions were about 1 and 1/2 mile off - the GPS put their location in the southbound lane of Interstate 29!
Just be careful using it.