You'll have to define what you actual goals are - ie what do you want to do with that information. Obviously you are not the police (and I would be shocked if the the police would do anything with any information you provided them) so I don't know how you plan to interact with any offenders. We don't need to know, but you need to define this with your neighbors IMHO.
That being said, I'm not sure what type of system/software can be used to detect stop sign violations. It seems like it would require some pretty complicated detection algorithms.
There are a lot of people on this forum that capture plate information. Some of us just record LPR footage without the need to identify cars/plates (I currently fall into this category) to have for the "just in case" scenario. But many members go a step further and use software to pull the plate data from their LPR footage, send that plate data to a paid service, and get vehicle registration and ownership records back. You'll have to decide which you want to have. There are lot of threads here that talk about how to set that type of system up if you are interested.
The good news is that the hardware is basically the same for either use case. You can start with the simple captures and always add the subscription records element in the future.
I doubt anyone uses cloud storage for this use case. First, it is unreliable. Second, it is expensive. Having a local NVR or
BlueIris system is definitely the way to go. (Blue Iris probably being the better option if you want to add a subscription record service - although since I haven't actually done that myself, I don't really know if it is possible with an NVR or not).
As far as giving access to multiple people, it really just depends on what your level of network knowledge is. I think the best way to handle this would be to have the BI machine setting in a sort of network DMZ (demilitarized zone) which can be accessed from the WAN but not have access to the rest of the LAN. This could be as simply as creating a VLAN with only the BI machine and/or LPC camera on it and giving those people VPN access to it (while blocking the VLAN from accessing any other part of the LAN), but that would require that everyone knows how to use a VPN. Another option would be to set up some sort of public server/device (ie your BI machine or LPR camera with remote login capabilities turned on) in a true DMZ that these people could access. I'm sure you could lock it down (as much as possible) from outsider by having some sort of strong login mechanism. This way people could just type in an internet address on any device and log into the server, but of course that poses a much larger security risk since the server/devices would be exposed to the internet. That being said, the "damage" done by a hacker would be minimal since it would be the only thing exposed to the WAN (as long as everything is set up correctly). In either case, you'll likely need to use a
DDNS (dynamic DNS service) to allow a static domain name to be used that will point back to the systems public IP address (that likely changes if you are using a residential internet provider).
Of course all of that is coming from a non expert when it comes to IT - so take all of that with a grain of salt. I know just enough to be dangerous, but not helpful enough to actually set something like that up!
