Unable to open certain sites over wifi

I noticed from time to time, but it is rare. This one finally got me to post see if I can find why.

Took a trip to San Diego in a car rental. Certain map app, not Apple, got me on a toll road. Fast forward now I got the letter about paying when I didn't pay at the time. I try to log on from my Mac Pro 1.1 running latest Lion and the page for South Bay Expressway Pay By the Plate site won't open. I head the the homepage and it opened once or twice then I get the same issue. I can go to any other site, but that one.

I tried iPad Mini……..same issue.

I booted into Bootcamp Vista with Chrome………sam issue can't open he page.

I tried my iPhone 5S………..still can't open it. I asked a friend to open that page and her iPhone 6 opened it just fine. She was out and about.So I turned off wifi on my iPhone 5S and I was able to open the page. At the time of this post I still can't open that page from my desktop and iPad through my wifi connection. All other sites both secure and public open just fine. No idea what is causing it. At this point it isn't an issue, but I am wondering why. I already rebooted the modem and Airport Extreme. Still can't open it.

Any ideas or suggestions?