[bartvk]

I wonder why they didn't opt for your suggestion for multiple modest projects.

The article doesn't mention it, it only says:

> National Park Service began a decades-long study of the region’s mountain lion population that the 101 freeway was deemed “the most significant barrier to the ecological health of the region.”

[eszed]

A big reason (this is from the project site):

> NEPA Completed 04/12/2018: Finding of No Significant Impact (FONSI), Liberty Canyon Wildlife Habitat Connectivity Project

> In compliance with CEQA, Caltrans held a 47-day public scoping period to allow the public and regulatory agencies an opportunity to comment on the scope of the IS/EA and to identify issues that should be addressed in the environmental document. A scoping report documents the issues and concerns expressed during the public scoping meetings held on January 14, 2016 and the written comments received from the public, community organizations, and governmental agencies during the public scoping period from December 14, 2015 through January 29, 2016. The release of the Final Environmental Document with responses to comments included was completed in the summer of 2016. NEPA/CEQA was completed in April 2018. A total of 8,859 comments were received in response to the draft Environmental Document, with only 15 opposed.

When any infrastructure project requires nearly a decade of preliminary work before shovels hit ground, said work becomes impossible to accomplish for smaller-scale builds. Even if ten smaller bridges would be a better solution, 10x-ing the review process would likely be impossible at current staffing / budget levels.

It's a big problem.

[Espressosaurus]

If it's too small/unsafe you'll end up with wildlife not using it or being funneled in for other for predators. The larger and more skittish the animals you want to use it, the larger you're going to want to make it. Since they're calling out mountain lions, which are quite skittish, they're going to need a large (and probably partially covered) pathway for them to want to use it--as opposed to treating the freeway like the barrier it is to wildlife.

I'm sure there's more to it than that, but making it desirable, accessible, and for it to feel safe for the target animal population is important for it to accomplish what it's intended to do.

There are smaller culverts all over the place for smaller wildlife. I've even seen some called out in small walking paths--there for the frogs and other amphibians.