NEW YORK, Jan 16 (Reuters) - Investment firm Pimco thinks it is unlikely that Washington will enact welfare reform or a major spending plan to improve bridges, roads and other infrastructure in 2018, Libby Cantrill, Pimco's head of public policy, said on Tuesday.

"While infrastructure was a key theme during the 2016 campaign and has strong support among Democrats on Capitol Hill, as of now, we do not see significant traction being made in 2018," Cantrill wrote in a blog post.

"We are similarly skeptical we will see anything meaningful passed on welfare reform," she added.

(Reporting by Richard Leong; Editing by Cynthia Osterman)