(CNN) -- Airlines hoping for exemptions at some airports to the tarmac delay rule going into effect next week are out of luck.
The Department of Transportation denied requests Thursday from JetBlue, Delta, Continental, American and US Airways for exceptions to the rule, which were prompted by runway construction at New York's John F. Kennedy International Airport, one of the nation's most congested airports.
"Passengers on flights delayed on the tarmac have a right to know they will not be held aboard a plane indefinitely," U.S. Transportation Secretary Ray LaHood said in a statement. "This is an important consumer protection, and we believe it should take effect as planned."
In its ruling, the department indicated that it may take the construction at JFK into account "when deciding whether to pursue enforcement action for failing to comply with the rule and the amount of the fine, if any, to seek as a result of noncompliance."
"We thank the Department for recognizing that there are unique challenges at New York's Kennedy and will take that into account when deciding whether to pursue civil penalties," American Airlines spokesman Tim Smith said in response to the ruling.
Airlines could re-route or reschedule JFK flights to minimize congestion, the department said.
"We are prepared to comply with the original ruling," Delta Air Lines spokesman Anthony Black said.
The rule, set to go into effect April 29, is designed to prevent planes on domestic routes from sitting on the tarmac for more than three hours with passengers on board. Airlines who violate the rule could face fines of up to $27,500 per passenger, the maximum allowed for violating any aviation consumer rule.
In March, JetBlue Airways asked for an exemption to the rule at JFK, where an extensive construction project has closed the airport's busiest runway.
Delta and American Airlines also requested exemptions at JFK, and Continental Airlines followed with its own request that added neighboring LaGuardia and Newark Liberty International airports.
US Airways asked for a similar exemption at its hub at Philadelphia International Airport, arguing that "it shares the same airspace, is part of the same air traffic control center (New York Center), and has the same congestion challenges as JFK, LaGuardia and Newark."
Airline passenger advocate Kate Hanni, founder of FlyersRights.org and a supporter of the tarmac delay rule, is pleased the exemptions were denied.
"We are both thrilled and gratified that DOT has taken a Hard Stand against long tarmac delays as a safety issue. We believe that 700 million travelers a year will benefit knowing they can reasonably predict the outcome of their flight knowing they cannot be held longer than 3 hours in a sealed metal tube!" Hanni said via e-mail.
Another passenger advocate, David Stempler, president of the Air Travelers Association, is opposed to the three-hour rule, stating that "placing time deadlines on safety related activities should never occur."
The rule "creates not only safety concerns for passengers, but misery in the from of many more cancelled flights," he said.
Stempler and other opponents of the rule say airlines are likely to cancel more flights during the busy summer travel season to avoid penalties incurred by long delays.