Can we do without installation of an air-release valve?
From my point of view the valve is necessary because the day you have to shut off the water, even if you bleed the system once it is turned back on, you will really appreciate having had the air valve installed.
Regarding road obstruction, you could install a remote air vent under the pavement or a smart valve purging system at the edge of the curb.
Every system, every network has its own hydraulic characteristics. It also depends on what it is used for: drinking water or wastewater?
To avoid expensive air-release valves, which aren't always useful anyway, we place a tee fitting at the high point with a wet connection and a 1/4 turn valve, which can be activated manually at roadside using a curb box for each component in case air needs to be cleared during overflow or purging/filling of the pipe. It's a good compromise. Recently installed on a 200mm-PVC pipe at 4 high points. No problem, as our pumps push well and the curve is generally upwards in spite of these high and low points. Otherwise yes, triple-function air release valve for wastewater or drinking water, depending on need and space constraints (but they do require regular maintenance). We also use small automatic air valves for drinking water connections, which are placed in flowmeter cabinet at the high points on the network. They work well and are inexpensive. For wastewater discharge, triple function air release/air in take valve or manual purge valve, if there is no possibility of a remote valve or a manhole deep enough to accommodate it.
And above all:
-avoid a chaotic pipe profile; sometimes it is better to have too much depth and avoid accessories that have to be maintained.
- prevent pump cavitation.
To contend that "the large number of street connections will allow sufficient air to escape" is not acceptable. If an air valve is necessary, then the best solution must be sought (see the alternative proposed by @Pateau01 )
The other advantage of an air release valve is it can also allow air in as the pipe is drained.