The district, Caldecott said, would have to prove that the driver was impaired before he started driving, but as of yet there are no legally defined standards or guidelines that address such an issue, according to Caldecott.
The same standards, or lack thereof, would also apply to teachers, Caldecott said.
Nonetheless, it's the policy of the district to maintain a drug-free workplace that is consistent with federal law, Caldecott said.
Proposition 19 would not, supporters say, prevent employers from maintaining a drug-free workplace or requiring them to come to work sober.
In addition, the measure would not legalize marijuana use for children.
Two weeks ago board member Martha Fluor asked district staff to review the implications of the proposition, which she said does spell out the obvious prohibitions: That is, the consumption of cannabis in any form in a public place, such as a school, is forbidden.
It also prohibits bits the consumption of cannabis by the operator of any vehicle, boat or aircraft while it is being operated.
However, what concerns Fluor is the language in the proposition that says, "No person shall be punished, fined, discriminated against, or be denied any right or privilege for lawfully engaging in any conduct permitted by the act or authorized pursuant to Section 11301 of this act.
"Provided however," it states, "that the existing right of an employer to address consumption that actually impairs job performance by an employee shall not be affected."
"My issue is with the use of the word 'actually,'" said Fluor. "The word seems to suggest that consumption prior to work would be prohibited only if it actually led to an accident or other tangible, observable impairment of performance, only after it is too late to prevent an incident."
The opposition resolution should be ready to be voted on during the next regularly scheduled school board meeting, which convenes on Oct. 7. Proposition 19 goes before voters Nov. 2. It will require a simple majority to pass.
Proposition 19 is also known as the "Regulate, Control and Tax Cannabis Act of 2010," which would legalize various marijuana-related activities while allowing local governments to regulate the activities and issue permits to collect and impose marijuana-related fees and taxes.
Yet even if the proposition passes, the sale of marijuana will be remain illegal under federal law.
Medical marijuana, also illegal under federal law, is legal in California and widely available.