The airline route-map adjustments may have slowed down in recent months, but Delta just made some notable network cuts.The Atlanta-based carrier trimmed three domestic routes during its latest schedule update, as first seen in Cirium timetables and later confirmed by an airline spokesperson.Delta is ending nonstop flights between the following three city pairs:Boston (BOS) and Toronto (YYZ).Detroit (DTW) and Oakland (OAK).DTW and Oklahoma City (OKC).Want more airline-specific news? Sign up for TPG’s free new biweekly Aviation newsletter.Interestingly, two of the three routes are actually “new” for Delta. Service between Detroit and Oakland is scheduled to begin in June. The original plan was for Delta to fly the route year-round with two-times-weekly service.However, the airline has seemingly been unimpressed with the booking curve for the winter months, as the airline will now scrap the service at the beginning of September. It’s anyone’s guess if the Oakland service will relaunch next summer, but in the meantime, Delta will continue serving the city from many of its other hubs.(Map courtesy of Cirium)The Boston to Toronto flight was also slated to be a “new” route for Delta. The airline hasn’t flown between the two cities since August 2013, based on Cirium schedules, and Delta made a splashy announcement in May 2021 touting the new route as part of a broader expansion in Boston.The route would have gone head-to-head with American’s new three-times-daily service (along with a plethora of daily flights on Air Canada and WestJet). At the time of Delta’s announcement, it was clear that the airline wanted to strengthen its appeal to locals in the Boston area.The airline’s Boston hub has been subject to intense competition from American and JetBlue under the so-called Northeast Alliance, a tie-up that’s focused on growth in the Northeast. Together, American and JetBlue have added hundreds of flights in both Boston and New York, and Delta has been feeling the heat.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.In fact, Boston to Toronto is a new market for American that was added in April 2022 as part of the Northeast Alliance. While Delta continues to add long-haul routes from Boston and promises to deploy its snazzy new domestic workhorse from the city, the airline doesn’t seem to feel the need to compete with American (and JetBlue) on the Toronto route.As with Oakland, Delta will continue serving Toronto from many of its other hubs.Finally, service from Detroit to Oklahoma City was suspended at the outset of the pandemic in April 2020 and was only scheduled to resume this September. Now, the route has been pulled entirely from the schedule, so it’ll be interesting to see whether the route ever relaunches.For its part, Delta says that these adjustments are part of the normal pandemic-era tweaks that it makes to its network. “We continue to evaluate our schedule and make changes based on customer demand trends,” an airline spokesperson told TPG.