What he says. Save the battery by driving on hold on the highway. The low speed driving that you will be doing on your deliveries will extend the range of the Volt. EVs are very speed sensitive, the slower you drive the longer you can go.Best way would to put it in hold mode on the highway, then when you start the paper route, switch to normal (electric). Normal is the most efficient mode for start/stop, and the gas engine will be OFF the whole time you are in normal mode. Should you run down the battery, no worries, the engine will start automatically and you will keep on driving on gas.
My 2013 Volt, after driving 15 miles in HOLD mode, would be good for about 40-45 miles on battery (in Houston, with the A/C running), but constantly starting and stopping will demand more power than steady driving. Even though you gain some due to regen when stopping, accelerating from a stopped position takes more power (try pushing your car from a stop and see how hard it is to get up to speed). So I would guess you might lose 10 miles of range on a stop-start paper route. You MIGHT make the whole 35 mile route on battery, then would use some gas for the 15 mile drive home.
The Prius, like any other car where the gas engine runs all the time, will get its worst mileage if constantly stopping and starting. The Volt should be better overall due to all the start-stop driving being in electric (normal) mode.
(from a former bicycle paperboy)