Since I'm optimistic about the HPS to LED changeout in my area, is it possible to get arrested by police by obstructing the electrician's or crew worker's job? I'm just being curious...

I would advise strongly against any confrontation, especially physical. Whether you or anyone else likes it or not, those replacing a street light are only doing their job and you getting in the way isn't going to do anybody any favours and will serve only to bring lighting collectors in general into disrepute.

If you're just watching them at a distance and you're not intentionally getting in their way, you're okay. It's also okay to go up to them safely and ask about a streetlight as I had done.

Really the only time police will come is if you're getting in their way, being disrespectful making threats or otherwise causing a scene lol.

Since I'm optimistic about the HPS to LED changeout in my area, is it possible to get arrested by police by obstructing the electrician's or crew worker's job? I'm just being curious...

When really obstructing their work? In any sane country definitely yes (if you insist on it into an extreme level). Remind you, as obstructing counts even being too close to make them too uncomfortable about your safety, or arguing about it.
When observing withut interfering? In a sane country no.
By politely asking to e.g. get what appears to become a scrap for them? Again no. But you have to accept any answer without arguing.

Since I'm optimistic about the HPS to LED changeout in my area, is it possible to get arrested by police by obstructing the electrician's or crew worker's job? I'm just being curious...

Why don't you express your concerns (with solid proof) to your public administrator instead?
Obstructing work won't change planned maintenance, maybe will result in a fine and definitively will ruin the day of the electricians.

This is coming from an electrician myself, it may sound harsh but we aren't getting payed to talk to you; only do what is asked of us and as quick as we can. If you are causing an issue and a few strong messages for you to take your business elsewhere, we can get law enforcement to take care of the situation. I have seen it happen a few times with people asking how to wire their house which is illegal here for anyone who doesn't have an 'A Grade' liscence. The best thing to do is not be pushing, if you get a no then just walk away and better yet, send an email to the company and ask for it there.

If you are obstructing any job site, law enforcement will move you on in the first instance, then if you refuse to go they will arrest you, releasing you later in the day with a caution. 
If on the other hand you cause any damage, then it will be a matter for the courts. 
Of course I can only say what would happen here in the UK, in your jurisdiction things might be handled differently.

 Well I tried save the OV35 and  Went on the property and nicely ask the forman if I can save some street lights in parking 
 Lot.  I well forman called police as i found out it as property belongs to city of San Antonio for flood control project.
 Basically escorted out.   Basically i could not save the OV
  35. 

   

I'll add, as a DOT employee myself, if anyone ever tried to obstruct myself or most of the members of my crew, we are either bigger than you and/or more obstinate than you and we'd basically walk around you or right over you to continue our work. Might even make you feel bad about yourself in the process. About the only thing that stops us is somebody who has open sores or isn't wearing pants. We've seen it all. Worse case, we come back another day. Never do we call cops.