Comprehensive
Transport Planning
Creating a Comprehensive Framework for Transportation Planning and Policy Analysis
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Victoria Transport Policy Institute
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Updated
22 July 2008
This chapter describes planning reforms for more comprehensive and accurate transportation decision-making. Conventional planning tends to favor mobility over accessibility and automobile travel over alternative modes. More comprehensive planning is particularly important when evaluating TDM and alternative modes. This chapter summarizes the report Comprehensive Transport Planning Framework: Best Practices For Evaluating All Options And Impacts at www.vtpi.org/comprehensive.pdf
Nonmotorized
Transport Evaluation and Planning
Impacts on
Transportation Options
Environmental and
Livability Impacts
Summary: Comparing Conventional and
Comprehensive Transport Planning
School
Transportation Solutions
Conventional
Versus Comprehensive Economic Evaluation
References And Resources For More
Information
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“The
most insidious form of ignorance is misplaced certainty” -Robert
Costanza |
When shopping for an automobile, consumers need accurate and comprehensive information about the vehicles they might purchase. Some information, such as a vehicle’s purchase price, design features and performance, is easily obtained from vehicle manufactures and dealers. But smart buyers want additional information that requires more research, such as each vehicle’s long-term operating costs, maintenance and repair costs, insurance costs, and future resale value. They should investigate whether a vehicle is particularly dangerous, unreliable, or vulnerable to theft. It is also important to consider whether a vehicle is suitable for the full range of uses it may need to serve, including its ability to accommodate people with diverse physical needs (large, small and disabled), carry various loads (luggage, sports equipment and lumber), and operate under a wide range of conditions (rough roads, extreme weather, steep inclines). These additional factors can be important. Often, a vehicle that seems best based on dealer data (lowest price, fastest, best sound system) is not the most suitable when all factors are considered.
Similarly, a community wants comprehensive information when making transportation decisions. Decision-makers need to know more than just construction cost and traffic performance, the factors that are easiest to measure and given the most attention in conventional transportation planning. They also need information on long-term and indirect impacts, its ability to serve diverse needs and operate under variable conditions. Often, a transportation decision that seems most effective at solving a particular problem is not the best approach when all factors are considered.
Conventional transportation planning and investment Models evaluate potential transportation improvements by comparing direct project financial costs with projected savings in travel time, vehicle operating cost, and crash costs (TTI, 1999; World Bank, 2000). For example, they predict whether a million-dollar roadway investment or transit service improvement will provide an estimated million dollars worth of travel time, vehicle cost and safety benefits over its lifetime. This type of analysis may be adequate when comparing options that are similar, such as alternative highway routes, but more comprehensive framework is needed when comparing options that involve alternative modes or TDM strategies, because such decisions have a broader range of impacts.
Decisions that affect the range of transportation options that will be available, or the total amount of vehicle travel that occurs in an area, should take into account additional factors. This chapter describes important factors that should be considered in transportation planning, which are often overlooked or undervalued. It describes these values, examines how they are treated under current planning practices, and identifies changes needed to make transportation planning more comprehensive and objective.
More comprehensive planning takes into account additional costs that often result from increased roadway capacity and the additional vehicle traffic it produces, and it takes into account additional benefits provided by TDM strategies that improve transport options and encourage more efficient use of existing transportation system capacity. These additional factors justify policy and planning decisions that emphasize increased transportation system diversity and efficiency.
This analysis indicates that current transport planning practices tend to be biased in various ways that overvalue highway capacity expansion and undervalue alternative solutions to transportation problems. Although individually these distortions may appear modest, often affecting just 5-10% of decisions, their effects are cumulative, and so together can significantly shift policy and planning decisions to favor automobile transport and reduce support for alternative modes and TDM solutions. These distortions result in economically excessive automobile travel (more automobile travel than would occur in a more efficient transportation market), which harms consumers and the economy overall.
Critics might argue that an equal number of distortions favor alternative modes, but there is little evidence that this is true. The only planning bias favoring alternative modes generally identified by critics is the claim that transit and non-motorized travel sometimes receive more than a proportional share of transport resources. For example, transit might carry only 3% of passenger trips in a region, but receives 20% of capital investments, or walking may only represent only 5% of commute trips, but 10% of roadway cross-section is devoted to sidewalks. Such claims tend to be based on selective analysis (for example, considering only certain transportation budgets, or certain geographic areas), and ignore various factors that justify additional public investment in these modes: transit and walking provide Basic Mobility and so are justified for equity and option value; these modes tend to be most cost effective on congested urban corridors where roadway capacity expansion costs are particularly high; and automobile travel involves additional public costs, such as parking facilities, congestion and pollution, that should also be considered when determining what constitutes a “fair” share of public expenditures (see discussion in Transit Evaluation). Such claims also reflect biases in how transportation is Measured, such as undercounting of non-motorized travel.
Systems Approach
To Transportation Planning
Many
experts are increasingly aware of the value of studying whole systems, rather
than simply examining a system’s components individually. This requires more
comprehensive research methods, but provides more useful information. For
example, in the past, agricultural biologists studied individual insect
species, perhaps to determine which pesticide is most effective at
controlling their infestations. But ecologists tend to consider additional
issues, such as the effects a insecticide has on other, non-target insect
species; whether it bioaccumulates and therefore threatens the insect’s
predators; and how changes in insect populations might affect other plants
and animals. Not only can ecologists predict potential problems that may
result from pesticide use, they may also be able to identify other ways to
control insect infestations, perhaps by stimulating the growth of natural
enemies. Other
disciplines also taking a more comprehensive approach to problem solving. A
psychologist deals with individuals’ problems, while social workers tend to
deal with families and communities. A medical specialist deals with a
particular organ or disease, while a general practitioner deals with the
whole patient. Transportation
planning is currently at a relatively crude level of development. We still
tend to use a narrow perspective when evaluating problems and solutions, and
as a result, we sometimes implement solutions to one problem that exacerbate
other problems, and fail to consider more integrated solutions that provide
multiple benefits. For
example, most local traffic agencies set generous minimum parking
requirements in order to prevent parking problems, although this tends to
exacerbate traffic congestion, sprawl and housing inaffordability, but few of
these agencies have implemented Parking Management
programs or established Transportation Management
Associations which can help reduce parking problems and address other
community objectives, because traffic agencies focus on a narrow set of
problems. There
are many other TDM strategies that help achieve multiple community
objectives. However, these solutions tend to face various barriers. When
potential benefits are considered individually, they often do not seem worth
the effort, except where a particular problem is extreme. A broader
perspective is needed to perceive the full benefits of these strategies,
therefore justifying their broader implementation. |
This section describes specific factors required for comprehensive transportation planning.
Comprehensive planning should consider a wider range of potential solutions to transportation problems, including alternative modes, demand management strategies, and integrated programs that involve a combination of strategies. For example, roadway projects (such as new highway lanes) can be more efficient and fair if funded through direct user charges, rather than indirect or general taxes, and transit projects may become more cost effective if implemented with TDM strategies that encourage transit use and create more transit-oriented land use patterns.
Current transportation planning and funding tends to be biased in favor of automobile transportation, and often overlooks other modes and management solutions to transportation problems. Automobile and air travel tend to be considered prestigious, and most transportation decision makers have more personal experience with driving than with alternative modes. Highway improvements are often justified on the grounds that they serve freight transport and therefore support economic development, even though they are actually used primarily for private travel, and alternative strategies (such as Freight Transport Management or Road Pricing) could improve freight transport for less cost. More technical resources are available for Evaluating automobile-oriented improvements than for other solutions.
Transportation planning often ignores TDM altogether, or only considers a few individual strategies which are familiar to the individuals involved. Innovative strategies, such as pricing reforms and land use management strategies, are often ignored. It is uncommon to include an integrated TDM program that includes a combination of complementary TDM strategies.
When developing alternatives, consider a variety of modes and demand management options. This can include pure TDM programs, and TDM programs integrated with road or transit projects. For example, a bridge or road project may be more cost effective if implemented with demand management strategies that reduce the project’s size requirements, or defers construction for several years. Innovative strategies, such as pricing reforms and land use management strategies, should be included even if they are unlikely to be implemented in the short-term, because they may become more acceptable in the future.
More funding tends to be available for roadway improvements than for alternatives. Highways are considered interregional and multi-modal facilities which serve long-distance travel and trucks and buss as well as automobile, and so are considered to deserve state/provincial and federal funding despite the fact that much of their traffic is local; while walking, cycling and public transit are considered local services that only provide passenger transport. As a result, more funding is available to accommodate local trips made by automobile than for local trips made by other modes.
Projects that involve a ribbon-cutting ceremony (e.g., new highways and transit services) tend to attract more political support, because they are considered more exciting and visible. As a result, investment practices often favor expenditures on large, new capital investments over operations and smaller, more incremental projects, operations (maintenance and management), even when they are most cost effective. In many situations, new transportation facilities are built while other facilities deteriorate due to inadequate maintenance, or service quality declines, due to inadequate operating funds.
A significant portion of U.S. federal and state highway funds are dedicated to roadway expenditures, and cannot be used for other investments, even if they are more cost effective. Some jurisdictions limit fuel tax revenues and other vehicle user fees to highway projects, while simultaneously using general taxes to also fund roadway facilities, resulting in cross-subsidies to driving (Puentes and Prince, 2003). In many cases, local or regional governments can obtain funding for roadway improvements, but not for other types of transportation improvements. This encourages local officials to define their transportation problems as traffic problems, rather than mobility problems or accessibility problems (Measuring Transportation). For example, a local government might be able to convince state or provincial governments to spend millions of dollars to build a highway off ramp to serve a school or commercial park, but would not obtain the same funds to run a shuttle service, subsidize a transportation management program, or relocate the school or stores closer to residential areas.
Current transportation planning and investment practices tend to favor expenditures on major capital projects over operations, maintenance and management activities, without consideration of which provides the greatest overall benefits (Meyer, 2001; Sussman, 2001). Many jurisdictions invest a large portion of their transportation budgets on new capacity, even though they have inadequate funds to maintain existing facilities or implement management programs that improve transportation services. A major portion of federal and state transportation funds can only be used for capital expansion. These practices result in poor maintenance of existing facilities, increased long-run costs, and they discourage management strategies that result in more efficient use of existing capacity.
This type of dedicated funding encourages local governments to choose highway projects over alternative solutions to transportation problems. For example, if local officials know that state and federal governments have money for highways, or offer greater matching grants for highways than for other types of projects, they will tend to define their transportation problems as highway problems, and will have less incentive to consider transit investments, road pricing or other TDM strategies.
Transportation planning and funding practices should give priority to maintenance and operations over capacity expansion, and apply Least Cost Planning principles, so that management strategies and incremental projects can be implemented whenever they are most cost effective overall. In general, preventive maintenance and management activities that result in more efficient use of existing capacity should receive priority over expenditures on new capacity. Traffic Operations programs, which improve roadway system performance, should receive support comparable to system expansion. A good policy, called fix-it-first, is to avoid expanding a transportation system if there is inadequate funding to maintain existing facilities and services.
Market distortions that underprice transport activity results in economically excessive travel demand (more than what would occur in an efficient market). Attempting to meet this demand results in economically excessive capacity, inefficient resource use, and exacerbates transport problems (Market Principles). It is akin to asking how many seats a restaurant would need if its prices ranged from fifty cents to a dollar per meal.
Automobile use is underpriced. Motor vehicles are expensive to own, but cheap to drive because most costs of motor vehicle use are either fixed or external (Transportation Costs). Although these price distortions may individually appear modest, their cumulative impacts are substantial. More efficient pricing of Parking, Roadway Use, Vehicle Insurance, and Environmental Costs would each reduce vehicle travel by 5-20%. In total, more than a third of motor vehicle use results from market distortions that underprice driving (Litman, 2001).
Conventional transportation planning attempts to meet this travel demand with little consideration of these price distortions. For example, ITE parking demand surveys are mostly performed at sites where parking is unpriced. These surveys are then used to establish minimum parking standards that are widely adopted into zoning codes and development requirements. This results in generous parking supply, low-density land use patterns unsuitable for walking and transit access, and makes it difficult to charge users directly for parking. This creates a self-reinforcing cycle of increased road and parking capacity, more Automobile Dependent transportation and land use patterns, leading to more road and parking demand, which justifies continual increases in road and parking capacity (illustrated below). Because of the increasing vehicle travel demand, congestion and parking problems are never solved, and other problems increase.
Transportation planning should consider the effects of market distortions on travel demand, identify the effects of specific forms of underpricing, and use pricing reforms to help solve problems. Where efficient pricing is not feasible, other TDM strategies should be used, as much as possible, as a second-best approach to encourage more efficient transportation and land use patterns.
Regional transportation Models, which are used to predict how changes to the transportation system impact travel conditions (e.g., how a new highway or transit service will affect traffic congestion and mobility) can significantly impact transport planning decisions. Such models are designed primarily to evaluate motor vehicle traffic, and tend to be inaccurate when evaluating alternative modes, demand management strategies, and small-scale projects. Yet, they are often used to evaluate a wide range of transportation alternatives. This often overstates the potential benefits of roadway improvements and understates the benefits of demand management strategies.
Transportation Models are frequently used to predict future travel conditions and evaluate different types of transportation improvements, including alternative modes and TDM strategies, although they are not sensitive to the effects of generated traffic, changes in travel options, transit service quality, price change, marketing incentives or land use factors (such as neighborhood walking conditions), and so are not very effective at evaluating alternative modes and other demand management strategies.
Many current models lack “feedback” (that is, they do not recognize that increased traffic congestion tends to limit further growth in traffic, and increased roadway capacity can generate additional peak-period travel). Such models essentially extrapolate past trends, assuming that vehicle travel demand will grow at historical rates regardless of what policies are implemented or the degree of traffic congestion that develops. Transportation modelers often treat travel demand as a fixed factor with only one or two variables (that is, they assume that a certain number of people will travel along a corridor), rather than a highly variable function that can be affected by many factors including roadway congestion, the quality of travel options, price, walkability, land use patterns and community attitudes.
The transit elasticity values commonly used in transportation models are largely based on studies of short- and medium-run impacts, performed decades ago when real incomes where lower and a larger portion of the population was transit dependent. The resulting elasticity values are probably lower by about half than what would accurately predict medium and long-run changes under current conditions. As a result, most transportation models significantly understate the potential of transit fare reductions and service improvements to reduce problems such as traffic congestion and vehicle pollution, and they understate the long-term negative impacts that fare increases and service cuts can have on transit ridership, transit revenue, traffic congestion and pollution emissions.
As a result, they tend to overestimate future traffic congestion problems, overestimate the benefits of roadway capacity expansion, and underestimate the potential benefits of transit improvements and other TDM strategies.
Use an advanced transportation Model that incorporates feedback and is sensitive to pricing, mode choice and micro-scale land use factors. If such a model is not available, insure that decision-makers are aware of the limitations of any predictions from the model, such as any tendencies to overestimate future traffic congestion problems, and undervalue TDM strategies. Future models may be able to evaluate accessibility rather than mobility, allowing more accurate analysis of travel impacts.
Transportation planners should not report travel demand as a fixed value (“traffic volumes will grow 20% over the next decade”), but rather as a variable (“traffic volumes will grow 20% over the next decade if current policies continue, 10% if a parking fee averaging $1.00 per day is implemented, and 0% if a $3.00 per day average parking fee is implemented.”) This helps decision-makers understand how travel patterns can be affected by public policy decisions.
How transportation is defined and Measured can affect which solutions are considered best. A particular policy or project may appear worthwhile when transportation system performance is measured in one way, but undesirable when it is measured another way. The ultimate goal of most transportation is Accessibility, the ability to reach desired goods, services and activities. Many transport projects improve accessibility by some modes, but degrade it for others. For example, increasing roadway capacity and traffic speeds tends to improve access by automobile but reduces it by other modes, such as walking, cycling and transit.
Vehicle traffic is relatively easy to measure, so transportation system quality tends to be evaluated based largely on automobile travel conditions (e.g., average traffic speeds, roadway Level-of-Service, vehicle congestion delay, vehicle operating costs, parking supply), while ignoring other accessibility impacts, including impacts on Transit Service Quality, Nonmotorized Transport and land use Accessibility. This tends to favor automobile-oriented solutions, and undervalues alternative solutions to transportation problems.
Since access is the ultimate goal of most transportation activity, it is important to develop ways to Evaluate Accessibility. Access should be evaluated from various perspectives, including those of different modes (driving, transit, walking), and different geographic and demographic groups (children, commuters, parents, elders) groups. Below are some suitable performance indicators:
· Multi-Modal Level of Service ratings.
· Average door-to-door commute times for residents.
· Average annual transportation expenditures per capita.
· Freight transportation delivery speeds and costs.
· Quality of Transportation Options.
· Quality of transportation options for non-drivers and lower-income people.
· Quality of the pedestrian and cycling environments.
· Land use Accessibility (e.g., number of jobs and public services within walking distance of residents).
· Crashes and crash fatalities per capita.
· User satisfaction survey results (for motorists, transit users, pedestrian facility users, etc.).
· Results of user surveys identifying access barriers and problems.
Countless decisions, large and small, made by a variety of public and private organizations affect transportation systems. Although strategic planning can affect some of these decisions, many are made without consideration of their indirect and long-term effects. The result can be a “tyranny of small decisions,” in which problems are exacerbated by a lack of coordination.
Jurisdictions within a region often compete for new development (particularly commercial taxes), resulting in decisions that contradict overall planning objectives. For example, urban fringe communities may offer tax discounts and lax environmental standards to attract retail businesses and industry, although it creates more automobile-dependent land use patterns.
In practice, this often gives large, new “masterplanned” communities an advantage over existing communities. Such communities are able to coordinate land uses, transportation facilities and facility design better than existing communities can. The result is degradation of older, accessible urban neighborhoods, while new masterplanned communities, often located in less accessible exurban areas, are able to provide more amenities that attract higher-income residents and successful businesses.
Current planning processes are often unable to coordinate smaller-scale individual decisions. There is often no mechanism to develop strategic objectives, prioritize transportation planning decisions among different jurisdictions and agencies, or enforce their implementation.
Establish strategic regional vision, goals and objectives that apply to transportation planning. Prioritize transportation decisions among different jurisdictions and agencies. Implement Smart Growth Policy Reforms as needed to encourage individual jurisdictions, agencies and businesses to support these goals and objectives in their decisions, both large and small. Create planning and enforcement mechanisms that allow existing communities too development quality comparable to what exists in new, masterplanned communities.
Urban traffic congestion tends to maintain a self-limiting equilibrium: traffic grows until congestion discourages additional peak-period vehicle travel. People shift their travel time, route, mode and destination to avoid congestion. If roadway capacity increases, they will take additional peak-period trips, including some that represent an overall increase in vehicle mileage (as opposed to simply shifts in travel time and route).
Generated traffic is a name for this additional vehicle travel that occurs when roadway capacity increases (Rebound Effects). This consists of a combination of diverted travel (vehicle trips shifted from other times and routes), and induced travel (travel shifted from other modes and destinations, and increased vehicle trip making). Under typical urban conditions, more than half of added capacity is filled within five years of project completion by generated traffic, with additional but slower growth in later years. Generated traffic has significant implications for transportation planning:
1. Generated traffic tends to
reduce the predicted congestion reduction benefits of increased road capacity.
2. Induced travel increases
external costs, including downstream congestion, parking costs, crashes,
pollution, and other environmental impacts, particularly if it leads to more
automobile dependent transport systems and land use patterns. These external
costs can be quite significant, often exceeding the magnitude of congestion
reduction benefits.
3. The additional travel that
is generated provides relatively modest user benefits, since it consists of
marginal value trips (travel that consumers are most willing to forego).
This is not to suggest that increasing road capacity provides no benefits, but generated traffic affects the nature of these benefits. It means that road project benefits consist more of increased mobility and less of reduced traffic congestion. Failing to consider generated traffic impacts can significantly reduce the accuracy of transportation policy and project evaluation. Modeling and planning practices that ignore these impacts tend to exaggerate the benefits of highway projects and understate the benefits of alternative modes and TDM solutions. Ignoring generated traffic impacts overstates the benefits of urban roadway capacity expansion project by 50% or more (Williams and Yamashita, 1992).
Most current traffic Models account for changes in routes and modes, and some account for changes from off-peak to peak periods that result from roadway improvements. However, few account for long-term changes in trips destinations, trip frequency, transportation diversity and land use patterns. As a result, they cannot account for a significant portion of generated traffic and the majority of induced travel that results from increasing the capacity of congested urban highways.
Current models also tend to ignore the demand-limiting effect of congestion. They often extrapolate past traffic growth rates to predict extreme levels of future congestion if roadway capacity does not increase, sometimes implying that the road system will reach “gridlock” This is almost never true. Traffic congestion will usually discourage further growth in peak-period travel demand, resulting in moderate, but never extreme levels of congestion on urban roads.
For these reasons, most current models overestimate future congestion costs, and the potential congestion reduction benefits of increased highway capacity. They also tend to ignore or underestimate the additional downstream congestion and parking problems, consumer costs, pollution emissions and sprawl that results from highway capacity expansion.
Traffic Models can be upgraded to predict the amount of vehicle traffic that would be generated by a highway project (Harvey and Deakin, 1993; Loudon, Parameswaran and Gardner, 1997). Such models can provide more realistic predictions of future congestion problems and the congestion reduction benefits of increased roadway capacity. They can also indicate the amount of additional vehicle travel that will be induced, allowing the incremental external costs to be estimated.
Solving a traffic bottleneck at one location may increase traffic congestion problems elsewhere in the road network. For example, increasing the capacity of a major highway may increase congestion problems on surface streets, particularly if it generates additional peak-period vehicle trips. On the other hand, a Transit Improvement or TDM strategy that reduces total vehicle traffic on the corridor avoids this impact, providing additional benefits by reducing congestion on surface streets.
Roadway capacity expansion projects are often evaluated based only on impacts on that particular link, without consideration of congestion impacts on other roads or in other jurisdictions. If a regional traffic Model is used but does not account for induced traffic (described above), it too will understate downstream congestion impacts. These practices tend to overstate the benefits of roadway capacity expansion, and the potential benefits of TDM alternatives.
Transportation projects should be evaluated using a comprehensive regional traffic model that incorporates generated traffic impacts, or simply by estimating the portion of additional roadway capacity that will be filled with generated and induced travel, and assigning this additional traffic congestion cost value.
For example, a highway capacity expansion project is projected to result in 1,000 additional peak-period vehicle trips each weekday, these trips are estimated to involve an average of 2-miles of travel on surface streets, and surface street peak-period congestion costs are estimated to average 15¢ per mile, this downstream congestion would impose annual costs of $150,000 (1,000 trips X 2 miles/trip X 2 trips/workday X 250 days/year X 15¢/mile). This is the additional annual cost assigned to the highway capacity expansion option that would be avoided by transit improvements, rideshare programs and other TDM strategies that avoid generating additional surface street traffic.
Transportation planning decisions can affect consumers in many ways, including the travel options, speed, comfort, safety and prices they face. Yet, existing evaluation practices tend to focus on just one or two impacts, particularly vehicle traffic speed, and ignore other factors that may be of equal or greater importance to users. Such practices tend to favor transportation improvements that increase mobility while undervaluing other types of improvements.
Existing transportation Models tend to focus primarily on travel speed when Evaluating transportation planning options. They assume that any increase in travel time increases consumer costs, and any reduction in travel time provides consumer benefits. They tend to undervalue or ignore altogether other factors, such as transportation system Diversity, comfort, safety and physical activity.
These models ignore the possibility that travelers may sometimes prefer slower modes. For example, many people enjoy walking and cycling and will chose them for some trips even if they are slower. Consumers sometimes consider time spent walking and cycling a benefit rather than a cost as indicated by the popularity of recreational strolling and cycling. Similarly, some people prefer ridesharing or transit because they find it less stressful than driving.
The assumption that any mode shift increases consumer costs is clearly incorrect for strategies that rely on positive incentives. With such incentives, travelers who continue driving are no worse off, but they have improved transportation options or financial rewards for using alternative modes. As a result, travelers only change mode if they are directly better off overall.
Treating any increase in travel time as a consumer cost tend to favor transport improvements that increase vehicle mobility, and undervalues TDM strategies that increase access or improves transportation options.
Consumer impacts should be Evaluated using consumer surplus analysis. This is particularly important when evaluating alternative modes, Land Use Management and Pricing Policies. Evaluation practices must recognize the benefits to consumers from strategies that improve consumer options or use positive incentives, even if they result in slower travel or reduced mobility.
Parking is one of the largest costs of motor vehicle use. A typical parking space has an annualized value of several hundred dollars a year (Parking Evaluation). Roadway projects that generate additio