The link (http://www.ntta.org/AboutUs/Traffic?tabid=speed) is the page you go to if you go to www.ntta.org and then click on "go to driving conditions map" towards the bottom right. The problem is that in Firefox/IE when you go to that page there is no info box in the upper left of the map, then you hover over a highway segment and the box pops up. In Safari/WebKit you have to first move your cursor in and out of the boxes that are already there until they are all gone, then you can finally hover over highway segments to see a sepcific set of times.
Additionally, Firefox displays a nice fade-out effect for the box. The box is hidden with CSS style "filter:alpha(opacity=0);-moz-opacity: 0.0;". Filter is an IE extension, and -moz-opacity is, obviously, a Mozilla one. I'm not sure if any of these should be implemented in WebKit - if not, this is a evangelism bug (because WebKit does implement CSS3 opacity). See also: bug 9210.
Well however this ends up getting fixed it would be nice to have it finally fixed. I tried contacting the website support people for the website directly a while back to report that Safari/Webkit doesn't work correctly but I never heard back.
Please contact the site owner and recommend that they include the W3C standard implementation for Opacity in addition to the other browser specific hacks. Something like: filter:alpha(opacity=0);-moz-opacity: 0.0;opacity:0" should float their boat. http://www.mandarindesign.com/opacity.html has a good review and the W3C recommendations are here: http://www.w3.org/TR/css3-color/#transparency
I tried contacting the website about this for the second time but I still haven't ever heard anything back from them. They do claim Safari compatibility and the rest of their website works well with Safari.
I think the reported site works actually properly in the latest WebKit. I compared it with Firefox and saw no difference. So the bug is fixed. Jordan, feel free to reopen the report you found other glitches.