https://www.selleckchem.com/products/adavivint.html OBJECTIVE Electronic dance music (EDM) party attendees are a high-risk population for drug use and associated adverse effects. We examined trends in past-year drug use within this population to better inform prevention and harm reduction efforts. METHODS Each summer from 2016 through 2019, we used time-space sampling to survey a cross-section of adults entering EDM parties at randomly selected nightclubs and at dance festivals in New York City. Ns ranged from 504 (2019) to 1,087 (2016). We estimated log-linear trends in past-year use of 16 different synthetic drugs or drug classes. RESULTS Between 2016 and 2019, estimated past-year prevalence of use of ketamine increased from 5.9% to 15.3% (a 157.6% relative increase; P = .007), LSD use increased from 9.9% to 16.6% (a 67.7% relative increase, P 3 drugs increased from 12.7% to 20.5% (a 61.4% relative increase; P = .013); however, estimated past-year use of unknown powders decreased from 2.0% to 1.1% (a relative 44.7% decrease; P = .038) and ecstasy/MDMA/Molly use was stable across years (at 25.0 to 28.5 %; P = .687). CONCLUSIONS Reports of powder cocaine, LSD, ketamine, and GHB are becoming more prevalent among EDM party attendees. Prevention and harm reduction efforts are needed to address increasing use. Research is also needed to examine whether increasing media coverage of medical use of ketamine and other psychedelics affects prevalence of recreational use. Advance guide signs for exit ramps along urban expressways are increasingly critical, enhancing safety and mobility by improving the flow of vehicles exiting urban expressways. However, research has devoted scant attention to advance guide signs for exit ramps. This study aimed to identify and propose optimal design alternatives for exit ramp advance guide signs for different types of exit spacing. This study conducted a driving simulation experiment consisting of five design alternatives of advance guide si