Just saw this on Wikipedia:
http://en.wikipedia.org/wiki/File:Downtown_Houston_1971.jpg
In mirroring the image to correct perspective, the gantry has the following legend:
"Texas Avenue
Harrisburg" as the mainline
and
"Gulf Fwy
Rusk" at the exit
Here's the signbridge in question - with no signs - nearly 40 years later:
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=1+Shell+Plaza,+Houston&sll=37.0625,-95.677068&sspn=41.275297,68.027344&ie=UTF8&hq=1+Shell+Plaza,&hnear=Houston,+Harris,+Texas&ll=29.764198,-95.378508&spn=0,0.002076&t=k&z=19&layer=c&cbll=29.763443,-95.378839&panoid=_zCl2ERWb8x4_DxevGNQzw&cbp=12,101.61,,0,-1.74
why did the photo get mirrored in the first place? Hopefully someone will upload the corrected version soon
Here ya go, i got bored so here:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_WYYeXvkUoUE%2FTD_ggeFcwGI%2FAAAAAAAAFqs%2FwVcrQXryhSo%2Fs800%2FHouston.jpg&hash=50c8ea58a5ce8058aebca842cd789e30c144c652)
BigMatt