So I've done some digging around and it seems like the trademark CalTran underpass soffit luminaires are made by a company called Sequoia Lighting and they have a bunch of spec sheets for them. Their site is a little broken so I direct linked the spec sheets below.

Cast Aluminum Housing

Century 2000 Soffit Luminaire Overview

Cross Sections and Catalogue Numbers

Remote Ballast Box for Soffit Luminaires

Soffit Luminaire Accessories

Soffit Luminaire Glass Refractors

Soffit Luminaire Ballast Kits

Apparently a LED retrofit kit was also made but I haven't been able to find any details about it.

Thanks for finding out who made these! Would be cool to find an older spec sheet that shows the mercury options and the flat glass.

I've also seen some of these pendant mounted as well.

So I've done some digging around and it seems like the trademark CalTran underpass soffit luminaires are made by a company called Sequoia Lighting and they have a bunch of spec sheets for them. Their site is a little broken so I direct linked the spec sheets below.

Cast Aluminum Housing

Century 2000 Soffit Luminaire Overview

Cross Sections and Catalogue Numbers

Remote Ballast Box for Soffit Luminaires

Soffit Luminaire Accessories

Soffit Luminaire Glass Refractors

Soffit Luminaire Ballast Kits

Apparently a LED retrofit kit was also made but I haven't been able to find any details about it.

Thank You I saved these PDF files encase they go down due to "Link-rot" as in the URL changes or the site goes down. I hate that manufactures can't find any information on old discontinued items on their own web page as in no records or matches electronics makers are especially true about that.

No problem, I was pretty interested the details of them too. Yeah I don't know how much longer they'll be online so I recommend saving the PDF files to your computer. They shouldn't take up that much room on your computer.

Yeah agreed, finding spec sheets for discontinued stuff is hard sometimes. More often than not, it seems like the distributors are more likely to have older spec sheets online or at least for the stuff I've searched for like older (mid 2000s) luminaires and ballasts.