Freezing rain at the onset of a protracted precipitation event helped cause hundreds of accidents across central and northern New Jersey on the morning into the mid afternoon of the 18th. New Jersey State Police alone responded to 428 accidents and 186 calls for assistance. A couple of accidents resulted in fatalities.  There were also numerous pedestrian slip and fall accidents. Mass transit was also impacted.  All New Jersey Transit bus service was suspended on the morning of the 18th. Tickets were cross-honored on all means of public transportation.
A confluence of meteorological events made it easy for roadways and walkways to freeze quickly. Eventual rain on the 12th washed salt off of roadways. The 17th was a cold day with high temperatures barely, if at all, getting to the freezing mark. Skies started clear on the evening of the 17th and temperatures dropped quickly. The onset of precipitation on the morning of the 18th (from south to north freezing rain began between 630 a.m. EST and 8 a.m. EST) occurred rather quickly after skies became cloudy and temperatures had little time to rise. Temperatures were as low as the middle 20s when freezing rain began. The early morning arrival of freezing rain in most places also negated any indirect heating of paved surfaces by the sun. Overall ice accumulations were less than two-tenths of an inch, but because icy conditions developed nearly instantaneously, driving and walking were extremely hazardous. Warmer air at the surface moved in as the 18th progressed and the freezing rain changed to plain rain between 10 a.m. EST and 3 p.m. EST. The freezing rain lasted the longest in the valleys of northwest New Jersey.
In Hunterdon County, a crash on Interstate 78 in Lebanon Borough killed a 64-year-old woman. The crash occurred when a sedan carrying two passengers slammed into the back of a salt pick-up truck.  The woman was a passenger in the sedan. The driver and other male passenger were also injured.  In Gloucester County,  in Mantua Township, a 22-year-old man died on New Jersey State Route 55. He was driving a pickup truck in the  northbound lanes when he apparently lost control of the vehicle while negotiating a curve and struck the metal post for the sign indicating Exit 53. In Camden County, in Bellmawr, a fire truck responding to a one-vehicle crash on Route 42 was damaged when it was hit by a car. Over a thirty minute span, an additional eleven vehicles were not able to stop in time and crashed into crashed vehicles. Three people, including one fire fighter were injured and required hospitalization. In Somerset County, a three vehicle accident occurred on U.S. Route 22.  In Middlesex County, both South and East Brunswick reported dozens of traffic accidents as well as several slip and fall accidents. In Mercer County, Rosedale Avenue in Princeton was closed because of icy conditions.
New Jersey Transit suspended all bus service statewide on the morning of the 18th.  Service resumed in the southern half of the state at Noon EST and in the northern half of the state service was resumed as conditions warranted.  Transit tickets were cross-honored. Speed restrictions were in place on the entire length of the New Jersey Turnpike as well as on the Garden State Parkway in Monmouth and Middlesex Counties.  All major bridges crossing the lower Delaware River into and around Philadelphia were closed for several hours: The Commodore Barry, Walt Whitman, Ben Franklin and Betsy Ross.

Representative ice accumulations included two-tenths of an inch in Butler (Morris County), one-eighth of an inch in Bridgewater Township (Somerset County), one-tenth of an inch in Perth Amboy (Middlesex County),  three-hundredths of an inch in Trenton (Mercer County), two hundredths of an inch in Sussex (Sussex County) and traces in Readington Township (Hunterdon County) and Sewell (Gloucester County). Precipitation spread northward along the eastern seaboard from an inverted trough that extended northward from Georgia into the Delaware Valley. Because there was a broad south to southeast flow aloft preceding a cold front that was in the Ohio Valley on the morning of the 18th, warmer air at the surface was moved into the area and eroded and eliminated all sub-freezing temperatures as the day progressed.

Winter Weather in GLOUCESTER, NEW JERSEY
From 18-JAN-15 06:30:00 to 18-JAN-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CAMDEN, NEW JERSEY
From 18-JAN-15 06:30:00 to 18-JAN-15 09:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Winter Weather in NORTHWESTERN BURLINGTON, NEW JERSEY
From 18-JAN-15 07:00:00 to 18-JAN-15 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Winter Weather in MERCER, NEW JERSEY
From 18-JAN-15 07:30:00 to 18-JAN-15 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Winter Weather in HUNTERDON, NEW JERSEY
From 18-JAN-15 07:30:00 to 18-JAN-15 10:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in SOMERSET, NEW JERSEY
From 18-JAN-15 08:00:00 to 18-JAN-15 10:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Winter Weather in MORRIS, NEW JERSEY
From 18-JAN-15 07:30:00 to 18-JAN-15 14:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Winter Weather in WARREN, NEW JERSEY
From 18-JAN-15 08:00:00 to 18-JAN-15 14:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Winter Weather in SUSSEX, NEW JERSEY
From 18-JAN-15 08:00:00 to 18-JAN-15 15:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Winter Weather in MIDDLESEX, NEW JERSEY
From 18-JAN-15 08:00:00 to 18-JAN-15 10:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper