Usually yes, if your dog fits in a carrier. Most big US transit systems let small pets ride inside a closed carrier and do not allow a pet dog on a leash. But there is no national rule, since every agency writes its own, and the exceptions are large. Boston allows leashed dogs outside rush hour. Seattle started letting leashed dogs ride in a pilot announced in October 2026. San Francisco's Muni charges your dog a fare and asks for a muzzle. Caltrain, on the same peninsula, doesn't take pets at all.
We read the rules for 10 systems on their own pages in November 2026. For New York, including the subway, LIRR, Metro-North, NJ Transit and PATH, see our separate guide to bringing a dog on the NYC subway. For intercity trips, see our Amtrak pet policy guide, which also covers Greyhound and FlixBus.
Public transit pet rules at a glance
| System | Leashed pet dog? | Carrier rule | Worth knowing |
|---|---|---|---|
| Boston, MBTA | Off-peak only | Small animals in a carrier, on your lap if possible | Dogs can't take a seat; staff can restrict access |
| Seattle, Sound Transit | Yes, short leash (pilot) | Cats and other small pets in secure carriers | Pilot runs through spring 2027 |
| San Francisco, Muni | Off-peak, leashed and muzzled | Other pets in a small closed container | Pays a full fare; one pet per vehicle |
| Bay Area, BART | No | Secure, enclosed carrier made for pets | Emotional support dogs need a carrier too |
| Peninsula, Caltrain | No | No pets allowed | Service animals only |
| Chicago, CTA | No | Small pets in a closed carrier that fits under a seat | One person must be able to carry it |
| Philadelphia, SEPTA | No | Standard sturdy pet carrier | Applies to comfort animals too |
| Washington DC, Metro | No | Secure container; small animals ride free | Container can't take a seat from riders |
| Los Angeles, Metro | No | Enclosed carrier | Can't block aisles or doors |
| Portland, TriMet | No | Secure, enclosed carrier | Covers buses and trains |
Boston: MBTA
The T is one of the few big systems where a large dog can ride without a carrier. The MBTA subway guide says small animals like cats and rabbits should be kept in pet carriers, on your lap if possible and away from the doors, especially at rush hour. Larger dogs are not allowed during peak hours. Off-peak, they are allowed but should be leashed at all times and can't take up a seat.
The MBTA's own pages don't quite agree on what "peak" means. The subway guide gives 7 to 9 a.m. and 4 to 7 p.m., with large dogs allowed from 9 a.m. to 4 p.m. and after 7 p.m., while its rider etiquette page says 7 to 10 a.m. Use the longer morning window to be safe. Staff can also restrict pets based on crowds or a dog's behavior, and the agency suggests skipping holidays and big events like the Boston Marathon. Pets are not allowed on The RIDE paratransit service, which takes only ADA service animals.
Seattle: Sound Transit
Seattle has the newest policy on this list. Sound Transit's pet policy pilot, announced October 28, 2026, covers Link light rail, Sounder trains and ST Express buses, and runs through spring 2027. Dogs can ride in a carrier or on a short leash. Cats and other small pets have to be in secure carriers.
Pets can't occupy seats or block aisles or doors, you need to clean up after your dog, and aggressive animals are never allowed. Because this is a pilot, the rules may change when the agency writes a permanent policy, so check before you rely on it for a regular commute. Remember too that other local bus agencies in the region set their own rules.
San Francisco: Muni
Muni has the most detailed rule we found. The SFMTA pet policy bars pets from Monday to Friday, 5 to 9 a.m. and 3 to 7 p.m. Off-peak, only one pet per vehicle can ride. Dogs must be leashed and muzzled and can ride only on your lap or under your seat. Other pets must be in a small closed container, also on your lap or under your seat. You pay a fare for your pet equal to your own.
The one-pet limit means you can be turned away if another pet is already aboard. Train your dog to accept a muzzle before you need it, and use a basket style that lets them pant. Some third-party sites still list older hours, so go by the agency's page.
Bay Area: BART and Caltrain
These two systems serve the same region but have different rules. BART says all non-service pets, including dogs whose only role is comfort or emotional support, must travel in a secure, enclosed carrier made for transporting pets. A tote bag wouldn't obviously qualify, so use a real pet carrier.
Caltrain is the strictest system here. Service animals may ride, and the page says, "No other animals (such as pets) are allowed." There is a narrow exception for 4-H volunteers raising guide dog puppies. So you can't take a pet dog on Caltrain from San Jose to San Francisco, even in a carrier, and you'll need to plan around it.
Chicago: CTA
The CTA rules allow only small pets, inside a closed protective carrier designed for travel that one person can carry. It must fit under a seat, although it can rest on your lap, and it can't block seats or walkways. You are responsible for your animal's behavior, and the CTA can remove any animal that acts aggressively or poses a direct threat, including a service animal. A big dog on a leash isn't an option on the L.
Philadelphia: SEPTA
SEPTA says pets can only be on its property in standard sturdy pet carriers. Carriers can't obstruct anything and the animal can't be disruptive. The rule specifically includes companion, therapy, comfort and emotional support animals. "On SEPTA property" also means stations, not only vehicles, so have your dog in the carrier before you walk in.
Washington DC: Metro
WMATA's tariff says pets, exotic animals and emotional support animals can't ride Metrorail or Metrobus unless enclosed in a carrier. Small animals ride free if they are securely enclosed in a kennel, cage, box or other container, and small enough to be carried without danger or offense to other riders. A container can't take a seat if that keeps other passengers from sitting. You may see a website claim that no pets at all are allowed, but that doesn't match WMATA's own document.
Los Angeles: Metro
LA Metro says pets and emotional support, therapy, comfort and companion animals need to be secured in enclosed carriers, and can't block the aisle or a doorway or interfere with other riders. Its customer code of conduct says only service animals or animals in carriers are allowed. Other agencies operate in LA County too, including local city bus lines, and they set their own rules.
Portland: TriMet
TriMet allows pets, including dogs and companion animals, on buses and trains only in a secure, enclosed carrier. Service animals can ride without a carrier, though your driver may ask you to confirm that yours is a service animal.
The rule most systems share
If your city isn't listed, assume a closed carrier until you've read the agency's own page. Search the agency name plus "rules of conduct" or "pets," since the rule is often buried in a code of conduct or FAQ. Look for four things: whether a leash is ever allowed, any peak-hour ban, whether a fare applies, and whether the rule covers stations as well as vehicles. If the page says nothing, call customer service before you make a trip that depends on it, and keep in mind that a driver or station agent can still make the call on the day.
Commuter rail often differs from the city system it connects to. A dog that's fine on one network may be refused on the next, as Caltrain and BART show. Check every leg of the trip, and have a backup plan for the last few miles.
Picking a carrier that passes
Words matter in these rules. "Secure," "enclosed" and "made for transporting pets" all point to a real carrier with a closing door or zip, not an open tote with a head sticking out. Choose one your dog can stand and turn around in, with a firm base and good ventilation, that you can lift by yourself up a flight of stairs. Our reviews of the best dog backpack carriers and best cat carriers for travel are a good place to start.
Let your dog get used to it well before the ride. Short practice sessions at home, followed by a brief trip at a quiet hour, make a big difference. Avoid crowded trains and hot days, and take your dog for a toilet break first. If your dog gets carsick, our guide to motion sickness during travel can help.
Service dogs and emotional support dogs
Every rule above treats trained service animals differently. They generally don't need a carrier, and under the Americans with Disabilities Act they don't need a certificate. Emotional support dogs get no such exception. BART, SEPTA, WMATA and LA Metro all say so directly, and a letter won't change that. Our guide to service dog public access rights explains what staff can and can't ask.
When your dog won't fit
If your dog is too big for a carrier and your city doesn't allow leashes, you still have options. Many rideshare drivers will take a dog if you ask first, as we explain in our guide to bringing a dog in an Uber or Lyft. Local pet taxis handle vet trips and airport runs, and many will wait while you run an errand if you ask when you book. For a move across the state or the country, a door-to-door ground transporter is usually easier than stringing together public transit with a large dog.
Planning by the size of your dog
A small dog that fits in a carrier has the easiest time, and can ride nearly every system on this list. The exception is Caltrain, and Muni's peak-hour ban. Keep the carrier on your lap or under the seat, and it's unlikely to bother anyone.
A medium dog is the awkward size. It may be too heavy to carry comfortably, but the carrier rules still apply in Chicago, Philadelphia, Washington, Los Angeles and Portland. A wheeled carrier may help, but check that it meets the local wording, and remember stairs and broken elevators. Before you buy, ask whether the agency's staff would count it as a closed carrier.
A large dog can really only use Boston off-peak, or Seattle during the pilot. Muni's lap or under-seat rule makes it unrealistic for a big dog even outside peak hours. In other cities, plan on a car or a pet taxi from the start.
Cats and other small pets
Cats have an easier time with these rules, since nearly every agency already treats a closed carrier as the standard. The carrier matters more than the species. Choose one your cat can't push open, line it with something absorbent, and cover it with a light towel to cut down on noise and movement. Sound Transit's pilot, for example, gives only dogs a leash option, and cats and other small pets have to stay in secure carriers. Don't take your cat out on board, however quiet the car looks.
Being a welcome rider
Most of these rules let staff or other riders' complaints decide what happens, so behavior matters as much as the written rule. Pick off-peak trips, and stand or sit near the end of the car, away from the doors. Keep your dog on the floor, not a seat, and pack waste bags and something to clean up an accident. Some riders are allergic to or afraid of dogs, so give them room and move if somebody asks. A dog who barks or lunges at other riders can get you removed, even on a system that allows pets.
If a driver or station agent refuses you, don't argue on the platform. Note the route, time and vehicle number, and contact customer service later. Staff generally have the final say at that moment, and you may need another way to get there, so keep a rideshare app and the number of a local pet taxi on your phone.