Environmental Impact of Transportation

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Introduction • To assess the environmental impact of a proposed development (be it a housing project, a new industry, a new highway, etc.), the transportation impacts must always be examined and quantified • We sometimes think of transportation impacts as singularly traffic air pollution, but the impacts are much wider

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Introduction •Transportation impacts differ from many other environmental impacts since they may be more severe at a considerable distance from the development location (e.g. traffic congestion, noise, etc.) •These impacts which are mainly adverse, can be divided into the following four categories:

• Vehicular impacts • Safety and operational impacts • Roadway impacts • Impacts during construction

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Introduction •Vehicular impacts:

• Noise pollution • Vibration • Air pollution • Litter • Anxiety resulting from the traffic generated by a proposed development, a road improvement or a traffic management scheme

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Introduction • Safety and operational impacts:

• Impact on the existing roadway system including additional delays to all road users

• Roadway impacts (infrastructure impacts): • Visual intrusion • Severance • Disturbance of archaeological, historical or amenity areas • Effects on the aquatic ecosystem • Demolition of property

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Introduction • Impacts during construction:

• Impacts of construction traffic and other temporary disturbances such as those resulting from temporary diversion of streams, construction noise, etc

• In some countries the safety and capacity impacts of road construction and improvement proposals are considered separately from the project environmental assessment

Transportation & Development

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• Motor vehicle is a profligate user of energy & land and a large source of pollution • We have made transport vital to both our economic & social well-being (production & distribution of goods & services depend on it) • Economic development has always followed the available lines of communication •In EU about 10% of GDP & 9% of employment generated by transport industry • >90% of motorized person trips and >80% of all freight movements are by road

Transportation Planning

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• Traffic congestion & its associated environmental effects are among the most obvious problems in urban areas • Large increases in car ownership & use are predicted everywhere • There is general agreement that car traffic must be restrained in urban areas but none of the existing traffic policies has been effective in reducing car use except to a limited extent in the centers of large cities • Commercial vehicle use also continues to grow

Matrix of Environmental Impact & Transportation System Stages

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• In evaluating potential environmental impacts of any proposed change in the transportation system, the following questions should be asked for each of the six environmental subsystems: 1. Is there a potential impact on the environment,

and is it positive or negative? 2. How serious is such a change? 3. What is its expected magnitude of change? 4. How certain is the effect to occur? 5. What further assessment or research is

required?

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Typical environmental impacts resulting from transportation operations and infrastructure construction

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Environmental effects, including health effects, might occur in any of the four stages of the transportation system: • Production of vehicles and fuels • Construction of the transportation infrastructure • Operation of the transportation system • Decommissioning and disposal of vehicles and infrastructure

Matrix of Environmental Impact & Transportation System Stages

Environmental Effects of Roads & Traffic

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Vehicular Impacts

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• These are impacts on the receiving environment caused by the traffic generated by a proposed development

• Noise • Vibration • Air pollution • Litter • Physical damage • Anxiety

Noise

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• Traffic noise can interfere with speech communication, can disturb sleep and relaxation and interfere with the ability to perform complex tasks • Surveys in many countries have shown that traffic noise is one of the principal environmental nuisances in urban areas • Noise is frequently used in the assessment of road proposals and traffic management schemes

Noise

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• Noise criteria •There is general agreement that traffic noise (and industrial noise) can be appropriately measured in A-weighted (decibels, dBA) units • An increase of 2 or 3 dBA is just noticeable while an increase of 10 dBA approximates doubling of loudness • Either the LAeq or the LA10 averaged over a specific time period is normally used

• A 12 hour period (08.00 to 20.00 hours) is often used with the LAeq •An 18 hour period (06.00 to 24.00 hours) is usually associated with the LA10

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Noise

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• Noise thresholds • The severity of a noise problem is usually indicated by the extent the noise level exceeds a threshold or standard value of a specified noise criterion (e.g. LA10 of 18 hour period) • There are no universally accepted threshold levels but it is generally accepted that outdoor noise levels above 70 dBA constitute a problem • A WHO task group has recommended daytime noise limits of about 55 LAeq as a general health goal for outdoor noise in residential areas •At night, an outdoor level of about 45 LAeq is required to meet sleep criteria

Noise (Major factors affecting traffic noise)

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• Noise generated by stream of traffic depends on • Traffic volume and speed • Traffic composition (% heavy vehicles) • Road gradient • Traffic flow conditions (free flowing or stop & go) • Road surface type and irregularities

• Noise level at reception point is influenced by: • distance from road to reception point • height of the reception point above road • intervening ground surface conditions • presence of obstructions • presence of nearby buildings (reflect noise)

Methods of Reducing Impact of Traffic Noise

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Example of Traffic Noise Level Calculation

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Traffic-Induced Vibrations in Buildings

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• Airborne vibrations (caused by low-frequency sound (50 to 100 Hz) by large vehicle engines & exhausts) • Groundborne vibrations (caused by varying forces between the tyres of heavy vehicles & road surfaces which result from irregularities in the road surface (8 to 20 Hz)) • Vibration measurement and thresholds (expressed in terms of peak particle velocity (p.p.v.))

• The following threshold values are often used: • Perception = 0.3 mm/s (p.p.v.) • Annoyance = 1 mm/s (p.p.v.) • Structural damage = 10 mm/s (p.p.v.)

Air Pollution from Vehicles

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• The major sources of atmospheric pollution caused by motor vehicles are from exhaust gases, evaporative losses from the fuel tank and carburettor, crank case losses and dust from tyres (rubber), brake linings and clutch plates (asbestos) • Typically vehicular air pollution is less than that from industry & homes but, with increasing vehicle numbers, is a serious concern in urban areas • Vehicle exhaust gas is divided into noxious and innocuous compounds

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Typical pollutant levels in highway environments

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Vehicular emission rates of pollutants

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Threshold limit value of air pollutants

Example of Air pollution calculation

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Vehicular Impacts

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• Vehicular-borne Litter (Litter is reported as a major environmental nuisance in public opinion surveys and certain areas can be spoiled by car-borne litter)

• Abandoned cars and illegal dumping may also constitute problems • The provision of convenient litter receptacles appears necessary in such circumstances since exortation or enforcement alone are often insufficient

• Physical Damage • To the road pavement, roadside objects such as signs, footpaths and gateposts, particularly on narrow roads • Vehicles splash pedestrians in wet weather • Require adequate road maintenance & design, heavy vehicle entry restrictions & enforcement

Vehicular Impacts

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• Anxiety (feeling of not being safe are strongly associated with heavy vehicles & with high speeds)

• Older people are particularly affected as parents who worry about their children safety on the roads; parents of young children who cycle are especially worried • An allied environmental impact is the disturbance to social life by not being able to talk on the footpath because of passing traffic • The implementation of traffic calming methods such as speed control and heavy vehicle restrictions can reduce these vehicular impacts

Safety and Capacity Impacts

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• Accidents • Traffic generated by a proposed development may affect the safety of existing road network, particularly if there is a high accident rate at present • Accident records & rates on the existing network should be examined for a period of three years • Comparisons with national accident rates for similar road types should be made

• Effects on Operation on Roads & Intersections • These include effects on traffic congestion & delay and on parking • The capacities of the existing roads & key intersections can be estimated from the appropriate road design standards manuals

Roadway Impacts

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• Visual Intrusion and Aesthetics • Scenic incompatibility • Obscuring of existing views • The creation of gaps in the urban fabric • Loss of sunlight • Loss of privacy

• Severance (occurs when a new development forms either physical or psychological boundary)

• Facilities to which access is inhibited • Catchment areas for those facilities • Numbers and types of persons affected • Levels of traffic causing the severance • Extent of mitigation of road crossing difficulties

Roadway Impacts

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• Land Consumption and Loss of Property • Number of properties demolished is an important measure of impact of transportation development • Other impacts such as displacement & relocation of people, loss of recreational areas may also be significant and should he quantified

• Changes in Land Access and Land Values • Transportation improvements may result in either increased or decreased access to adjacent properties • Increased access can sometimes lead to undesirable developments and decreased land values • Decreased access can cause problems for emergency & service vehicles & may lead to other detrimental effects, particularly for commercial properties

Construction Impacts

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• Traffic generated by construction of new development can cause major impacts, particularly for those living along routes used by this traffic • Since construction is labour intensive, large numbers of cars access construction sites at the start and end of the working day • The noise a& vibration from heavy vehicles disturb roadside residents, traffic delays occur, mud is deposited on t roads and the road pavements & verges may be physically damaged • Although construction impacts are of temporary duration they can be severe & can last for a considerable period

Traffic Generated by Proposed Developments

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• Car Traffic • Volume of car traffic attracted to a development depends on type & size of development, its location & on the number of employees a& their car ownership level

• Light Goods Vehicles • Number of delivery vehicles & other light goods vehicles & their distribution throughout the day will depend on activities being carried out at development

• Heavy Goods and Public Service Vehicles • Number of heavy vehicles required to service activities to be carried out at a development & their routing must be estimated by an examination of the projected level of these activities & of the likely origins & destinations of deliveries

Environmental Impact Assessment of Proposed Road Developments

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• A typical EIA for a proposed road would include: • A summary of the proposed road development and of the principal environmental impacts • General project description and a description of the alternatives considered • A baseline survey of the existing environment • Assessment of the environmental impacts • The implications for the land use and development plans for the affected area • The financial implications • Mitigation measures proposed to reduce the negative impacts • A synoptic table summarizing the individual impacts and costs for each of the alternatives considered

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Generic checklist of impacts

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Typical assessment techniques for environmental impacts