New York Codes, Rules and Regulations
Title 17 - DEPARTMENT OF TRANSPORTATION
Chapter V - New York State Supplement To The National Manual On Uniform Traffic Control Devices For Streets And Highways-2009 Edition
Part 2 - Signs
Chapter 2C - Warning Signs And Object Markers
Section 2C.117 - SMOKE Sign (NYW7-17)

Option:

01 The SMOKE (NYW7-17) sign (see Sign Drawing SD-W24) may be used, as necessary, to warn of locations where smoke from brush fires or forest fires drifts across the roadway.

02 The SMOKE sign may be supplemented with an Advisory Speed plaque (see Section 2C.08), where appropriate. Where smoke drifts intermittently across the road for a distance of 1000 feet or more, the SMOKE sign may be supplemented with a Distance plaque (see Section 2C.55).

Guidance:

03 The SMOKE sign should be removed as soon as the smoke is no longer present.

04 Where the SMOKE sign is supplemented with both a Distance plaque and an Advisory Speed plaque, the Distance plaque should be placed above the Advisory Speed plaque.