No you cannot stop a UPS truck to get your package.
The UPS driver will only deliver the package to the address on the package to ensure it gets to the correct person.
Also the UPS driver has a route they have to drive to get the packages delivered and the packages are arranged in the UPS truck following that route.
So they won't sift through or sort through the packages to find your package.
You can although have your package rerouted to a place such as your work or someone else's address if you do it in time through the UPS website.
But UPS drivers won't give you the package unless you're at the address it's being delivered too.
Just wait for it and if they are getting close to you then you should get it that day if it's on the truck out for delivery.