Expired ID becomes a big problem if an individual needs a document notarized. Without identification (in California) the signer must have two individuals, with ID, swear for their identity. If the signer can not produce the two individuals then the document is unable to be notarized.
I was recently confronted with this issue when I unable to notarize a document for a senior citizen because of expired ID. I felt really bad because the daughter was coming out from Las Vegas to have her mother sign a POA (power of attorney) so she could move her to a care facility closer to her but there was nothing I could do without proper identification.
The California DMV does offer a senior citizen ID card that is good for 10 years. It is offered free of charge. You must be 62 or older to apply for the card.
More senior driver information can be found here.