It might be possible for there to be two car insurance policies in one household depending upon the insurance company(s) involved and the circumstances.
We have seen where two auto insurance polices for the same household can be held. This can include a married husband and wife who want to retain their own separate policies or a situation where there is a child who has their own car, separate from their parents, and thus their own policy.
Some companies will not allow it because of state laws and liability exposure.
Typically it is cheaper to have members of a household and their vehicles on the same policy since there can be a multi-car discount. Also in general insurance companies will require all licensed household members to be listed on a policy, so even with separate polices, each insurance provider will likely require the other household members to listed on each other's polices. This can add expense.
If you or members of your household are in need of auto insurance quotes you can get them here online.