I dont recall workers being in Civ1, iirc, settlers made improvements and built roads.
That was the same in civ2. Also the concept of buying tile improvements was implemented was tried in Call to Power. Your civ generated public works and you can spend them to make improvements. Can't remember how well the community liked this.
But it would probably fit in with the ciV theme where money can buy anything. Although implementing this for the AI would be troublesome.