Dispatch: “Ambulance 1, report of an injury accident, Valley Highway southbound at Broadway.”
Ambulance 1: “Enroute, southbound Valley Highway at Broadway. Do we know if that is north of or south of?”
Dispatch: “Sorry, no.”
In this situation, picture that Valley Highway runs north-south through your jurisdiction. Broadway is one of the exits off of the highway. One mile north is Martin Luther King Boulevard and one mile south of Broadway is Main Street. You are posted at Valley Highway and Broadway.
You have two options. First, you can get onto the southbound highway at Broadway. If the crash is south of, you are golden and on the scene quickly. But if you miss the wreck, you have to go to the Main Street exit, head two miles northbound to MLK Blvd, then go back south. The other option is to take other streets to enter the highway at MLK from the start and go south to Broadway. But if the wreck is just-south-of Broadway, you look foolish.
Which should you choose?
As near as I can tell, the math essentially works out as a coin toss (assuming that there is a 50-50 chance the crash is north of or south of). Assume the crash is a half-mile from Broadway for our example, to make the math easier. If you get on the highway southbound, you will hit the crash in a half mile 50% of the time, but you will have to drive 3.5 miles half the time. So southbound averages out to 2 miles. If you go up to MLK, you will drive 1.5 miles (1 mile up to MLK, then 0.5 miles to the MVA) half the time and 2.5 miles (an extra mile to get ½ mile south of Broadway) the other half of the time. Which still averages out to two miles. So that is unhelpful.
Again, which should you choose: Access the highway at Broadway or MLK?
My answer depends on the fact that many drivers are not especially aware of their surroundings. “Completely oblivious” is a phrase that some people might use to describe the situation. When they see an accident and call 911, they are no less unaware. It’s a sad fact, but people don’t usually know where they are. All they know is that they are on Valley Highway between home and work, between daycare and home, whatever. Their specific location, not so much - some people might not even know that they are on Valley Highway.*
My bet is that the 911 caller saw a crash and knows that he is southbound on Valley Highway, but not specifically where. In may cases, a normal caller knows he’s by that gas station with the nasty bathroom, or he’s near that one taco joint that Sally likes, whatever. I’m even guilty of it; the only reason I know where I am is that I drive enough to recognize landmarks and such quickly enough to answer. But when dispatch calls me, I have to look around real fast and figure out where exactly I am (our response to dispatch being our current location, in theory).
Here is a tip that isn’t quite 100% true, but usually works out in your favor: People state their location on a highway as being at the next sign that they see.
Back to the 911 caller in our imaginary crash. They call 911 and read the next sign: “Valley Highway at, uh, Broadway.” See crash, call 911, read the sign talking about the next exit. So your best bet is to assume that the southbound crash is just north of Broadway; in this case between MLK and Broadway. Eastbound crashes are usually just west of, northbound crashes are just south of, southbound crashes are usually just north of, and westbound crashes are just east of. I don’t know for sure, being a city medic, but I wouldn’t be surprised if rural medics see the same pattern except with mile markers or distances to towns.
Pay attention to your next few runs that are called out with a vague location like this and see if it is true. I guarantee it works out much more often than not.