|The table below includes routes 200, 201, and 203, the precursors to the 500 system. 203 was designated on August 1, 1938, and the others (200 and 201) were designated in 1936. 202 was skipped because of US 202. The 200-series county routes were posted with state-style shields. In early February 1942, civil defense 5xx routes were established in New Jersey, New York, and Connecticut. There was some order to the system - 511 through 514 were all in Fairfield County, 524 through 528 were all in Queens and Brooklyn, and 545 through 549 were in south-central New Jersey. 503, 509, 532, and 540 all followed like-numbered NY routes (NY 303, NY 9A/US 9, NY 32, and NY 340), even if they continued into another state. The image at left is a diagram from the New York Times. The civil defense system numbered these roadways as alternatives to state highways in case the latter needed to be co-opted for emergency defense/military use.|
|In 1952, the civil defense routes were changed to the current 5xx system, with the county name in a square shield. Given that the civil defense routes were a tri-state system, as opposed to the geographic ordering of the modern 500 series, it's unsurprising that most of these numbers did not survive onto their current routes - in fact, a good amount of current 500 routes are not on former civil defense routes, and vice versa. 535 and 503 are two of the rare numbers that can be found in about the same place. 500-series routes are now primary county highways, numbered by the state but routed and maintained by the counties. The 2xx system was removed sometime after the 5xx system was adopted, although topo maps show it persisting into the 1960s. The first version of these shields were still embossed, such as the 506 shield at right (taken by NJRoadfan) in Montclair, which stood into the new millennium but is now gone. Some counties continued to use the square shield longer than others; the shield at left (from Chris Mason) is somewhat newer, as it is not embossed. Bergen County still has many square route shields posted, though not new ones.|
New Jersey was one of the first states to adopt the standard county pentagon, though as I just mentioned, some counties took longer than others. The 505 photo, taken by SPUI, looks white but is faded yellow; some New Jersey counties put "___ COUNTY" in white with the number in yellow, while other counties put everything in white, but all yellow (as in the 579 photo taken by Ray Martin) is standard.|
Recently, many Spur and Alternate county routes were decommissioned, leaving only one case of duplication, the two Spur 549s. Other routes, including two Spur 527s (one intersected I-78 at Exit 36, the other intersected NJ 24 at Exit 8), are replaced by 600-series secondary county routes, or in the counties that didn't adopt the 600 numbering system, other non-500 county routes. Where possible, these decommissioned routes are included in the table below and on the route pages, but I know that SPUI and I are missing information on earlier routes.