JMDiaz, Inc. (JMD), a California corporation, offers a full range of transportation planning and civil engineering covering highways, land development, traffic and rail projects for local agencies, railroads and private entities in California.

Originally founded by Juan M. Diaz in 2001, JMD is serving clients from its regional office in the City of Industry, California. Currently, JMD has a staff of 22 professionals and administrative staff.