As should be expected, Crotalus nails it. If human safety permits, move turtles and tortoises across the road in their direction of travel, and no farther. Certainly not to “that nice Park” or perhaps “that pretty stream” down the road.
Terrestrials like tortoises and semi-terrestrials like box turtles tend to be homebodies that should not be displaced from their home territories. And even aquatics may not benefit from your choice of a destination territory-- habitat differences that are too subtle for you to notice may make a huge difference to the turtle itself.
And then there is the possibility for translocation of diseases and parasites from one population to another. This is a serious threat, especially for the genus *Gopherus * (Desert Tortoise, Texas Tortoise, Gopher Tortoise, and others) which are subject to URTD (upper respiratory tract disease). URTD has many strains (like the flu) which are variable in morbidity and mortality, from highly lethal to merely nasty.
Being creatures of habit with self-restricted home ranges, natural spread of this disease syndrome can be limited. Tortoises in a given area become exposed over time to the local variant (call it URTD-A) and the survivors become resistant. But then along comes a do-good tortoise rescuer, bringing in a tortoise carrying another strain (say URTD-B). This displaced tortoise wanders hither and yon, searching for his home territory and spreading his disease variant throughout a population that is non-resistant to this different strain. And of course, becoming himself infected with URTD-A along the way.
Locally we see devastating effects on tortoise populations at popular destination locations, like state and national parks. Tortoises “rescued” from roadsides or construction locations all across the map are relocated by well meaning people, who think that the local park will make a swell new home for the individual animal. So the parks tend to accumulate tortoises carrying URTD-A through URTD-Z, each of which can separately infect every other tortoise on site.
Similar issues probably exist for even aquatic turtles, which can host a variety of parasites like flukes. Since many flukes require “intermediate hosts” in addition to “primary hosts” (I won’t elaborate, fearing a surplus of only tangentially relevant information) it is possible for one lake or stream to be fluke free, and another nearby to be heavily infested. Translocation of turtles can change these local conditions.
The bottom line is that relocation of wildlife, turtles and tortoises included, is more often deleterious than not, both to the individual and the population.