These icons () show footnotes as tooltips... for some browsers.
I-905 (proposed) California
Otay Mesa Road; formerly (before 1992) CA 117. Parts of the freeway exist today as CA 905. In 1969, this was proposed as an extension of CA 75.  It connects I-5 and CA 125, which is proposed to be extended south from I-8. CA 905 *might* become an interstate; it's been proposed for inclusion, but it's still officially CA 905. The San Diego Union Tribune even printed a correction for several previous articles that had jumped the gun and called it I-905. A San Diego Association of Governments brochure states that when the freeway is completed, "SR-905 WILL BE DESIGNATED AS I-905, as part of an obligation that is included in an agreement between the FHWA and the State of California."  However, 8.8 miles of CA 117 and 125 from I-5 to the border were approved as non-chargeable interstate mileage in October 1984. 
Currently the non-freeway part of 905 is a four/six-lane undivided road. San Diego, not the state, maintains this stretch; going east, drivers see "END CA 905" where the freeway ends (just beyond I-805); then, as the road hooks south to Mexico, "BEGIN CA 905". 
In August 1997, San Diego mayor Susan Golding lobbied for $220 million to finish 905. Among the 13 being wined and dined was Bud Shuster, who in effect said, "Sure, sounds great, but your congressmen need to support my 'Truth in Budgeting Act,'" which would unlock $33 billion from the Highway Trust Fund for a big tax-free bonanza for every congressional district. (I believe this would also take highways, or all of transportation, off budget, allowing Shuster easier access to federal dollars).
Since commercial truck traffic was shifted east to the Otay Mesa crossing in 1993, CA 905's fatality rate has been roughly five times that of similar rural roads. CalTrans has agreed to a $17 million interim solution: widening to six lanes and putting in Jersey barriers. (A similar barrier insertion was done in Northern CA to stop the bloodshed on CA 37.)