Throughout the 2016 presidential primaries, voters trying to cast a ballot have faced significant hurdles on election day. Some Arizona voters, for example, waited up to five hours because of too few polling places and mistakes with voter registration. A few poll workers in North Carolina required nonwhite voters to show their IDs and then, while not looking at the IDs, spell their names. Many Florida voters were turned away because poll workers thought only Republicans were voting that day. The mistake was fixed only after voters insisted that the Democrats were also holding a primary. Fortunately, there is a potent tool to fix these errors: checklists. All poll workers should have easy-to-follow checklists readily available at their precincts. Simple checklists have sharply reduced problems in other fields. Atul Gawande, a surgeon who writes for the New Yorker, demonstrated the power of checklists in his book A Checklist Manifesto: How To Get Things Right. Checklists have reduced infections during surgeries by almost 50 percent, saving scores of people from death or serious complications. They work in both rich and poor hospitals for all kinds of doctors. Checklists have helped builders construct skyscrapers without the risk that they will collapse, assisted pilots in landing distressed planes and showed stockbrokers which securities to avoid. Ever wonder why tall buildings hardly ever fall down? Contractors use various checklists to coordinate the many aspects of the building process so that each step is done in the correct order. Structural stability is ensured and the failure rate is reduced to almost zero. Pilots have a binder of checklists with them in the cockpit to handle various situations that could arise. They are trained to reference the lists immediately for the particular problem, as their memory and judgment are not necessarily reliable in a tense situation. Performing a surgery, landing a distressed plane and building a skyscraper share basic similarities with elections: They involve complex processes in which the potential for error is great and time constraints are tight. Checklists can help poll workers ensure they are doing things correctly. Poll workers generally have poor training and few tools to guide them when administering elections. They are inundated with too much complex information, rather than easily digestible instructions. Training manuals are too long, too technical and often do not address problems that might actually arise. Voters in Wisconsin, for example, experienced hours-long delays this year. Poll workers had a 154-page election-day manual, which obviously did not solve that problem. New York City’s election guide is more than 100 pages. No one should expect that a poll worker, who performs the job only every few years, will read an entire guide or remember everything in it. No wonder poll workers make mistakes that can increase how long it takes to vote or result in legitimate voters being turned away. There is a better approach: Give poll workers less information but focus on the vital items that have the potential to create mistakes. Poll workers need easy-to-use tools so they can reference them when problems arise, as they inevitably do each election. A polling station should have several checklists pasted to the table. One checklist could list the steps for processing voters who pose no obvious problems. Another would lay out what steps to follow if a voter’s name is not in the poll books or if an address is incorrect. States that require an ID could have a checklist for what to do if voters do not present valid photo identification. Voters, too, can benefit from checklists. There could be a pre-election-day checklist mailed to all voters on what to bring to the polls. Or states could provide a checklist for filling out an absentee ballot. Indeed, after Minnesota’s 2008 Senate election went to the courts because of issues with absentee balloting, the state reformed its voter instructions to include checklist-like guides with absentee ballots. The state has not had reported problems with absentee ballots since. The additional few seconds it might take for a poll worker to go through the checklist while a voter waits could pay huge dividends in the long run. Avoiding simple mistakes would likely mean shorter lines because voters would not be waiting for poll workers to figure out how to address a problem. More important, using checklists on Election Day could lead to fewer lost votes or disenfranchisement. It could even help avoid post-election disputes because there would be fewer ballots with potential errors to contest. Checklists offer an easy fix to some US election woes. County election officials can make checklists available at polling stations without the need for legislation or a major political battle. Existing training guides just need simplification and reformatting on the most critical items. Election-day checklists must be short — five to nine items is ideal. They should be simple and precise, and tested in simulations before Election Day as part of poll-worker training. Of course, checklists will not fix every potential problem, such as too few polling places. Yet most poll-worker mistakes stem from officials’ incompetence. Long lines, for example, are often due to poll workers not having the proper tools to assist them in handling various problems that occur in a high-stakes, high-turnout election. Checklists can help them avoid these simple errors. If election officials want to avoid the same kind of headlines that have plagued places like Wisconsin, with its hours-long lines, then the answer is simple: Use checklists to fix the process on the ground. Joshua A. Douglas, a law professor at the University of Kentucky College of Law, specializes in election law. He is the author of “A Checklist Manifesto for Election Day: How to Prevent Mistakes at the Polls,” 43 Florida State Law Review, and the co-editor of a new book, “Election Law Stories.”