Objective: To examine changes in travel distance and abortion incidence if Roe v. Wade were reversed or if abortion were further restricted.

Study design: We used a national database of abortion facilities to calculate travel distances from the population centroids of United States counties to the nearest publicly-identifiable abortion facility. We then estimated these travel distances under two hypothetical post-Roe scenarios. In the first, abortion becomes illegal in eight states with preemptive "trigger bans." In the second, abortion becomes illegal in an additional 13 states classified as at high risk of outlawing abortions under most circumstances. Using previously-published estimates of the short-run causal effects of increases in travel distances on abortion rates in Texas, we estimate changes in abortion incidence under each scenario.

Results: If Roe were reversed and all high-risk states banned abortion, 39% of the national population of women aged 15-44 would experience increases in travel distances ranging from less than 1 mile to 791 miles. If these women respond similarly to travel distances as Texas women, county-level abortion rates would fall by amounts ranging from less than 1% to more than 40%. Aggregating across all affected regions, the average resident is expected to experience a 249 mile increase in travel distance, and the abortion rate is predicted to fall by 32.8% (95% confidence interval 25.9-39.6%) in the year following a Roe reversal.

Conclusion: In the year following a reversal, increases in travel distances are predicted to prevent 93,546-143,561 women from accessing abortion care.

Implications: A reversal or weakening of Roe is likely to increase spatial disparities in abortion access. This could translate to a reduction in abortion rates and an increase in unwanted births and self-managed abortions.