I cant help with the history

I cant help with the history of them, but I mess around with them a lot at work, I really like the idea of modeling them on a layout. But my only two pointers for modeling them would be to put a hole in the center, this is what they use for moving them around, and also most of the ones I've been around are just brown, like the inside of a freight car wheel or the side of a rail. they usually have too much movement over them to allow enough rust to build up.

missabe406. Informative,

missabe406.

Informative, thank you.

I'll do one with a hole and put more RubnBuff on it to make it look less rusty and see how it turns out.

We have them,  and what was

We have them,  and what was said above,  they are polished and shinny black do to all rubber tires crossing them.  Now just seen on them including the ones that are not getting run over by traffic.

AzBaja, I see. Thanks. Now if

AzBaja,

I see. Thanks.

Now if I can only find out when these first appeared on roads.

When?

I remember seeing them in the early '50s and I have seen them in pictures back to the 20's. They probably go back as far as there have been paved roads and street departments to tear them up.

Lou

@Lou, Thanks. I recall them,

@Lou,

Thanks. I recall them, but never could remember how far back, as I never made a mental note of them.

I think I'll put one near this area on the road or lot.

Steel plating on roadways

Roadway steel plating began its use in the late 1930s as motor vehicles and trucks became heavier in gross weight, and steel is stronger yet lighter than iron. During World War II, steel rationing for the war effort limited use of this material as almost all metals were collected for war equipment production. It wasn't until the mid-to-late 1950s when the interstate roadway system construction commenced, and steel was the prime material used for bridge deck plating and temporary road work which held up well to vehicle traffic, and it is still in use today.

Steel plates

  I guess steel plates  were around earlier but I don't recall seeing many until the 60's . Seems before that contractors just barricaded off their trenches (with wooden barricades and oil wick lanterns up thru the 50s) till they got the pipe in then filled them a lot quicker than they do today. I do recall heavy wooden planking occasionally spanning ditches where it was necessary to cross them before back filling....DaveB

@draftpoint,  Very

@draftpoint, 

Very informative; thanks!

@DaveB,I recall oil wick

@DaveB,

I recall oil wick lamps that used to look like black bowling balls with a seam around them, as a kid.