PHILADELPHIA (CBS) – As the snow continues across the Delaware Valley, travel issues are expected to continue, and will likely worsen.

A snow emergency has gone into effect in Philadelphia, while one was already in place in New Jersey.

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Earlier today, PennDOT dropped speed limits on major roadways throughout Philadelphia including I-95, I-76, I-476, I-676, etc. to 45 mph and urged motorists to avoid travel if possible.  Early Friday morning, PennDOT lifted the speed limit restrictions.

(Credit: Jim Mekwert)

(Credit: Jim Mekwert)

SEPTA is running trains, buses and trolleys on normal weekday schedules, but they do warn that could change, especially the bus routes. If the route you’re using is normally impacted by snow, chances are it will be again today.

The following bus routes have been suspended due to poor road conditions: 18, 19, 35, 139, H, XH and L. The following routes are on detour: 7, 9, 14, 19, 27, 28, 31, 32, 38, 44, 48, 52, 55, 56, 58, 62, 65, 84, 88, 90, 92, 93, 95, 97, 98, 99, 103, 104, 107, 109, 110, 111, 112, 114, 115, 117, 118, 119, 120, 125, 126, 131 and G.

As of 7 p.m., SEPTA says Regional Rail service has resumed on the Chestnut Hill West Line. Operations on all Regional Rail lines have now resumed, however, passengers should expect delays.

In addition, SEPTA says some Regional Rail trains have been cancelled for tonight. For more information on these schedule adjustments, visit SEPTA’s website. Passengers can also contact SEPTA Customer Service representatives at (215) 580-7800.

Meanwhile, SEPTA said Market-Frankford and Broad Street Line trains will continue to operate during the overnight hours in place of Night Owl buses. After midnight, trains will run every 20 minutes. There is also no A-B skip-stop service on the Market-Frankford Line — all trains stop at all stations.

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Overall, SEPTA says riders should expect delays, and customers can call 215-580-7800 or visit their website for more information.

Amtrak is running on a modified schedule on the Northeast Corridor, which is affecting Acela Express, Northeast Regional and Keystone Service which again are running, but on a modified schedule.

Amtrak says service on the Northeast Corridor will also operate on a modified schedule on Friday. While the number of frequencies has been changed, a combination of Acela Express and Northeast Regional service is still planned to operate, with most adjustments between New York City and Washington, D.C.

In addition, Amtrak says Keystone Service between Harrisburg, Pa., and Philadelphia/New York City will operate on a modified schedule.

Philadelphia International Airport is reporting over 500 flights in and out of Philadelphia have been cancelled for today and say many arrivals through the late afternoon and evening will be delayed because of FAA traffic management. As of 2 p.m., the airport said there was a nearly 2.5 hour delay on arriving flights.

The airport also says the snow and cold temperatures Thursday night are expected to impact flight operations on Friday, especially in the morning.

If you’re scheduled to fly in or out of town, you are encouraged to check your flight status in advance by 1-800-PHL-GATE or by visiting the PHL website.

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Several accidents on the roadways in the area were causing detours and delays as well.