appendix a - Velocidade

Categories of road and vehicles chosen:
8
The effect of speed on noise, vibration and emissions
from vehicles
May 1998
cars and light vans: all trucks- with a vehicle mix of 85% cars and light vans: 15% trucks.
rural two lane roads: urban arterial roads
no gradient: +-10% gradient for rural roads: +- 8% gradient for urban roads (+3% gradient
was included to allow examples to be calculated for trucks travelling at constant speed)
with 20% or 80% of cars being equipped with catalytic converters
traffic flows 2000, 8000 and 15000 vehicles per day
vehicle speeds
urban roads cars 30, 40, 50, 60, 70 km/h
trucks 30, 40, 50, 60, 70
rural roads cars 60, 70, 80, 90 km/h
trucks 60, 70, 80, 85
Trucks are limited to speeds of 85 km/h so this is the highest speed that can be chosen for
this vehicle class.
1.2 OVERVIEW
The document is divided into this introductory section followed by descriptions of emissions,
noise and vibration.
Within each section a description of how the pollutant or noise is generated is given. The
effect of speed, acceleration and, where possible, additional effects of speed management
tools on the emission of the pollutants or noise are discussed. Additionally specific models
for estimating the emission of noise and pollutants are described.
A review of a number of specific emission models based on microscopic and macroscopic
simulations are provided in an appendix together with a description of databases of
emissions data.
Examples of the outputs from the two specific models described in earlier sections
(emissions and noise) are provided in separate appendices. These demonstrate the
relationship between speed and noise and emissions. The data in the appendices represent a
simplified case described in section 1.1.