ln order to explore the noise reduction potential of speed lowering measures, a great many of single vehicle pass-by measurements were conducted at different locations and with a large set of different vehicles. Some of the experiments were performed under freely flowing traffic conditions, in some experiments a known set of vehicles was investigated. For each vehicle the maximal pass-by level and the speed was registered in order to derive a speed dependent noise emission model. The different locations allowed for an additional investigation of the effects of road gradient and pavement type. A decrease of the vehicle speed from 50 to 30 km/h resulted in a reduction of the maximal pass-by level of 6 dB(A). This corresponds to a 4 dB(A) level drop in total pass-by energy. lt was found that even at 30 km/h the road pavement has a significant effect on noise emission. This is due to the fact that in modern passenger cars, rolling noise contributes substantially to total noise already at these low speeds. lt can be concluded that low noise pavements do make sense also in the context of low speed regimes.