After Hurricane Harvey struck southeast Texas last year, an Oklahoma church sent 150 people to help with disaster relief.

Before they left, church leaders worked to bolster safety on the nearly 1,000-mile round trip: They rented 18 newer-model vans and required volunteer drivers to complete an online training course.

This was in addition to making sure the vehicles, drivers, and passengers had insurance coverage.

"God forbid, if we had an accident with a van load full of people—you can run up some pretty high medical expenses," said John Trotter, elder and administrator for the Oklahoma church.

Managing the money of the church includes being up to date on insurance policies—knowing what types of coverage are essential, that policies include all possible drivers and vehicle scenarios, and that the limits are adequate.

Here are six questions to help church leaders when evaluating vehicle insurance coverage.

1. When does a church need vehicle insurance?

Of course, if a church owns a vehicle, it clearly needs a policy to cover that vehicle. Also, if a church plans to rent a vehicle, it needs appropriate insurance through its own company or through the rental company. (Whether or not to purchase insurance through a rental company is handled later in this article.)

In most cases, a volunteer driving his or her own vehicle on the church's behalf will need personal auto insurance, which typically will be that person's primary coverage. The church's policy generally is responsible for damages and liability beyond the personal auto policy, said Scott Figgins, vice president of underwriting for Brotherhood Mutual Insurance Company.

However, laws vary by state, so the church should discuss specifics with its insurance company.

Churches should discuss "non-owned and hired" (NOHA) insurance coverage with their agent, said Tom Strong, GuideOne Insurance's senior loss control manager. NOHA will offer protection when they rent a vehicle (hired) and when volunteers drive their own vehicles (non-owned), Strong said. In most states, for volunteers driving their own vehicles, their personal insurance is the primary coverage and the NOHA is for additional coverage.

Churches should make sure their policy includes noninsured motorist coverage, said Eric Spacek, GuideOne's former risk management and loss control director. That coverage is important "if you're involved in an accident, even if it's not the church driver's fault, but the other vehicle doesn't have coverage," Spacek said.