Please find the NON-emergency number and call that first. Let them know you want to make a test call and give them your number. This way when you call they are aware of it before you call and if they are busy, they may ask you to call at a different time. As someone who answers these calls, we don't mind test call at all, but most certainly appreciate previous notice. And like I said, we may ask you try at a different time. Something like an overheating car on the shoulder of the road can generate a ludicrous number of calls!
Be Safe