Voters will determine the next state Senator to represent portions of Cobb and Fulton counties in a runoff election May 16.

Democrat Christine Triebsch, a family and juvenile attorney, and Republican Kay Kirkpatrick, a retired orthopedic surgeon, will compete to replace longtime state Sen. Judson Hill, who vacated his seat to run for the U.S. House. The race attracted eight candidates — five Republicans and three Democrats — who competed on the same ballot for the state position.

With Hill, Republicans maintained a majority in the 56-member state Senate by a 20-member margin.

None of the eight candidates in the race neared anywhere close to the more than 50 percent mark needed to avoid a runoff. Triebsch, who received 24.2 percent of the vote, narrowly edged Kirkpatrick, who came in at 21.1 percent.

Kirkpatrick campaigned on a promise to increase public safety disaster preparedness, with an emphasis on addressing the Heroin and opioid epidemic, as well as simplifying the tax code and using conservative principles to change health care at the state level. She was the leading fundraiser with contributions from state Reps. Beth Beskin, R-Atlanta and Deborah Silcox, R-Atlanta, and U.S. Health Secretary Tom Price’s wife, state Rep. Elizabeth Price.

Triebsch, a political newcomer who raised the least amount of money among candidates, said her grassroots campaign resonated with voters.

Whoever wins the position will also have the power to help craft laws about local traffic — an issue of heightened concern following the collapse of a bridge on I-85 and the opening of SunTrust Park, the new home of the Braves franchise.