The table below summarizes the data taken from the case studies and allows users to more readily determine which of the case studies is most appropriate in their circumstances. The left hand column of the table divides the case studies into site specific, corridor level, and regional level analyses. The second column rates the level of practice as fair, good, and better. The right hand column names the case study so that that the users can look directly for the case studies that are most beneficial for their situation.
| Scale | Level of Practice | Credit Received | Sponsor | Strengths | Case Study Name |
|---|---|---|---|---|---|
| Site | Fair | TCM in GA SIP (no emissions credit received) | Private Sector | Proved Lower Emissions Over Conventional Development | Atlantic Steel (Atlanta, GA) |
| Region | Good | None | MPO | Technically Strong | Baltimore Metropolitan Council |
| Region | Good | None | MPO | Evaluates multiple land uses and transportation plans. Use of multiple performance measures and peer review process. | CAMPO |
| Region | Better | None | MPO | Technically Strong, Land Use Model | DRCOG (Denver, CO) |
| Region | Fair | None | MPO | Model for Entry-Level Practice | Mid-Region Council of Governments (Albuquerque, NM) |
| Region | Good | None | MPO | Evaluates Multiple Land and Transportation Plans | Lane COG (Eugene, Or) |
| Corridor | Fair | None | MPO | Recognized and Mitigated Local VMT Increases | MUMPO (Charlotte, NC) |
| Region | Good | None | MPO | Public Participation, Land Use Planning | SACOG (Sacramento, CA) |
| Region | Good | Plan Conformity | MPO | Done through Conformity Process | SANDAG (San Diego, CA) |
| Region | Good | None | MPO | Public Participation, Land Use Planning | Tri-County Planning Commission (Lansing, MI) |
| Site | Fair | SIP/CMAQ | Private Sector | Proved Lower Emissions Over Conventional Development | Woodlands Town Center (Houston-Galveston, TX) |
Scale - for which the analysis was performed. This factor is intended to give users some indication of whether or not this particular case study matches the scale of analysis in which they are interested. There are case studies at three scales: site specific, corridor, and regional level. Note that there is some upward overlap between the scales so that a site scale analysis may include elements of corridor or regional analysis.
Level of Practice - is an indicator of how the case study compares to the others in its application of tools. Level of practice is characterized as good, better, or best.
Credit Received -- indicates whether or not the project sponsor received formal emissions credit in either a state implementation plan or from the congestion mitigation air quality program.
Key Player - shows the driving party of the case study. While the key player may not have done most of the work they are the entity that is creating the desire to move forward on the project.
Strengths - indicates the notable features that can be cited as best practice for other, similar efforts.
In the Atlantic Steel case the Atlanta Regional Commission evaluated the potential emission change associated with locating a major development project in three different parts of the region. During 1998 the Atlanta region was in conformity lapse for ozone. During this lapse Jacoby Development Corporation sought to redevelop a 138-acre site near Atlanta's central business district at the interchange of I-75 and I-85 and across from 17th street. Because of the conformity lapse the 17th street bridge, connecting the development site with the transit station and providing access to the interstate could not be built unless the developer was granted flexibility under EPA's project XL provisions. The flexibility allowed the entire redevelopment to be considered a TCM. This included the location, transit linkage, site design, and other transportation elements. It also allowed an innovative approach to estimate the air quality benefits. The proposed development included approximately 17,500 jobs and approximately 6,000 people. Total growth for the City of Atlanta for the same time frame was 33,600 jobs and 18,200 people. Because the Atlantic Steel site was a downtown brownfields site, a group of stakeholders including the developer, Atlanta Regional Commission, USEPA, the Federal Highway Administration, Georgia Department of Environmental Protection, Georgia DOT, and local citizen groups used the opportunity to evaluate the benefits of the Atlantic Steel site as a brownfield redevelopment project.
The Atlantic Steel project included a multi-level evaluation of the proposed Atlantic Steel redevelopment project. The evaluation included comparisons of travel and emissions at both the regional and site levels, as well as local hot spot impacts. At the regional level the travel and emissions associated with the proposed project were compared with the travel and emissions that would result from adding the same development at three other around the Atlanta Metro Area. At the site level EPA analyzed the impacts of the different site designs. EPA found that the most regionally central, most pedestrian-friendly location and site design combinations, those at the Atlantic Steel location, produced the least VMT, emissions, and other environmental impacts.
The analysis of the Atlantic Steel site included regional and site specific analyses of trips and emissions. In the Atlantic Steel study the emissions effects of locating growth at one of four sites was evaluated. Because a no build or existing trends case were not included and the trip generation and distribution methodology was not clear, Atlantic Steel is not a complete template for supporting land use credit for either the SIP or a conformity determination. Although the proposal included accommodations for transit service, urban design guidelines, and performance monitoring, some aspects of the project such as increasing automobile accessibility and capacity packaged with the development; and the proposed presence of "big box" retailers on the site did not fit the traditional definition of smart growth.
The regional level analysis compares the travel and emissions resulting from placing the proposed development at the Atlantic Steel site and three other sites (one urban and two suburban) of approximately the same acreage. This analysis is in contrast to the other common practice of concentrating growth in a receiver area (or zone) while removing growth from widely dispersed donor areas. The regional emissions estimate was performed for VOC and NOx using the MOBILE model. Cold start emissions from each site were calculated separately for both VOC and NOx. A hot spot analysis for CO was also performed for the streets adjacent to the proposed Atlantic Steel site. The purpose of this analysis was to determine if the additional development and travel associated with the site would crate a localized violation of the CO standard. At the regional level the Atlantic Steel site produced less VMT and emissions than the other three sites. For the locations evaluated the proposed Atlantic Steel site resulted in estimated NOx emissions an average of 0.26 percent or 0.25 tons per day lower than the other sites. The proposed Atlantic Steel site resulted in estimated VOC emissions an average of 0.75 percent or 1.15 tons per day lower than the other sites.
In the site-specific analysis, the developer's original site design was compared with typical developments in the Atlanta area; a proposed new urbanist site design developed for EPA by Duany Plater-Zyberk & Company (DPZ); and revision of the original design that incorporated some of the DPZ design elements. The vehicle trips from the Atlanta Regional Commission travel mode were factored using elasticities to account for the increased diversity, varied design elements, and site density in the three site plans. All three of the proposed site plans resulted in lower estimated VMT and emissions compared to similar parcels in Atlanta.
From the report it is possible to infer the need for travel demand models that are sensitive to urban design factors and the need for emission models that can separately account for trip end emissions.
| Project Timeframe | Start: 1998 | End: 2000 |
|---|---|---|
| Data Inputs | All typical travel demand model inputs plus GIS based data on similar sites in the region and relative estimates of the urban design factors such as street slope, diversity, density, and walkability. This study also used an extensive urban design effort that was very costly. | |
| Data Outputs | Person trips, vehicle trips, transit trips, VMT, and emissions at both regional and site level. | |
| Sensitivity Analysis | Yes, at regional and site level. | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | Included in Georgia SIP, but no emissions credits were taken, which is fairly standard approach for other TCMs from the Atlanta region and is not indicative of any specific feature of this project. | |
Within the context of Maryland's smart growth initiative Baltimore is estimating changes to trip generation and mode choice based on housing density. The agency has focused on the changes in trip-making associated with land use and travel behavior but does not seem to have evaluated the effect on emissions or to have done a sensitivity analysis.
Baltimore applies differential trip rates at two points in the travel demand modeling process and estimates travel and emissions based on this two-level screen. Trip generation and mode choice both include a land use intensity or density variable estimated based on the 1993 Household Travel Survey. Trip generation and mode choice are influenced by the area type in which they occur.
In the trip generation portion of the model home based trip productions are estimated based on the number of household members and the average number of vehicles per household. Trip productions are then split into motorized and non-motorized parts using a logit model that includes a land use variable. A similar process is used for non-home based trips except that trip productions are estimated, by traffic analysis zone, and are allocated differently. The allocation uses a regression equation to synthesize trip origins and destinations. The 2000 model also includes a commercial vehicle (truck) model that estimates trip productions and attractions for commercial vehicles based on type of employment (retail, non-retail, and household) and the land use variable.
In addition to the work done on the 2000 model BMC participated in the add-on portion of the National Personal Transportation Survey and has new data on trip generation and mode choice. They are currently modifying their trip generation and mode choice modules to reflect this data. The revised models will include urban design level data such as sidewalks, street width, and street slope. This is in addition the current area type variable.
| Project Timeframe | Start: 1999 | End: 2003 |
|---|---|---|
| Data Inputs | All standard model parameters plus land use classification code. | |
| Data Outputs | All standard model outputs. | |
| Sensitivity Analysis | The model was compared to census data in the validation/evaluation process, but no formal sensitivity analysis was done. | |
| Cost-Benefit Analysis | None | |
| Land Use Control Strategies | None | |
Context In the Capital Area Metropolitan Planning Organization faced with multiple challenges while preparing the update of its long range transportation plan. The Research Triangle Area is a rapidly growing area. It is facing many of the challenges associated with rapid growth including suburbanization, habitat loss, and other quality of life issues. Among these issues was the recognition that USEPA was preparing to designate nonattainment areas under the eight-hour ozone standard. The MPO staff were seeking to proactively assess several land use and transportation plans that could meet transportation needs while maintaining the region's quality of life.
CAMPO staff used the newly developed Triangle Regional Model to evaluate five transportation options and five land use plans. The evaluation process was a 'hill climbing' technique in which all the transportation plans were evaluated using one land use and all the land uses were evaluated using the same transportation plan. The process also included a peer review panel that considered mobility, reliability, safety, water quality, open space environmental justice, economics, and air quality. Data management and evaluation were accomplished using spreadsheets.
As noted CAMPO evaluated five land use plans (mixed-use suburban, corridors and nodes, flexible growth boundary, adequate public facilities, and neotraditional/infill) and five transportation systems (current trends, intensive highway, managed lanes/rail, current trends plus rail, and intensive management/rail). A full estimate of emissions was prepared for the mixed-use suburban land use scenario and all five transportation systems. Using the current trend scenario as a baseline CO emissions changes range from a 3.4% increase to a 7.4% increase; VOC emission changes range from a 0.2% decrease (intensive management/rail) to a 6.4% increase (intensive highway); and NOx emissions changes range from an 18.5% decrease (intensive management/rail) to a 6.9% increase (managed lanes/rail).
This case is notable for the information given to the peer review panel. This information included emissions, travel times to key destinations, open space used, acres of wetlands affected, and historic sites near new construction.
| Project Timeframe | Start: 1999 | End: 2001 |
|---|---|---|
| Data Inputs | All standard model inputs plus multiple land uses and transportation networks. | |
| Data Outputs | Standard transportation model outputs VMT, travel times, congested links. | |
| Sensitivity Analysis | Yes | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | None adopted. | |
The Denver Regional Council of Governments was interested in quantifying the benefits and costs of promoting infill development in the Denver Region. Historically the DRCOG board had adopted an urban growth boundary. This study allowed DRCOG to evaluate the effect of different land uses inside the urban growth boundary. The DRCOG cooperated with the Environmental Protection Agency in evaluating the regional effects of changed land uses in the Denver Area. The study format benefited DRCOG by providing funding for this analysis and for improvements to their travel demand model.
In this project DRCOG staff evaluated three different land use patterns inside the urban growth boundary. The land uses evaluated were a continuation of lower density development throughout the urban growth area, concentrating growth in forty centers inside the growth area, and further concentrating growth in the centers inside the growth boundary. The changes in trip making and emissions were consistent with work performed by Charlotte North Carolina and Boston Massachusetts who also participated in this effort with EPA.
The DRCOG evaluated three land use proposals along while maintain a consistent transportation network. The total population and employment were kept the same, but the location of both population and employment were varied according to preset patterns. In all three scenarios the COG allocated 60 percent of growth using their land use model. In scenario A the remaining 40 percent was allocated to the urban fringe (outside the existing developed area), in scenario B the remaining 40 percent was allocated to thirty one activity centers (primarily in the older urbanized area), and in scenario C the remaining 40 percent of growth was allocated to ten large urban centers (primarily in the existing urbanized area).
Vehicle miles of travel ranged from a high of 92,308,000 in scenario A to a low of 88,966,000 in scenario C. Under the B and C scenarios motor vehicle emissions, and congested vehicle hours of travel drop while congested speed and transit shares both rise. Under scenario C VOC emissions drop by 4 percent, CO emissions by 3.6 percent, and NOx emissions by 3.7 percent or approximately 1,400 kg, 36,100 kg, and 1,100 kg respectively.
Mr. May noted the following needs in performing this type work: (1) real world data that quantifies the changes in trip making associated with changes to land use, (2) work on the internal capture rate of trips in mixed use developments, (3) work showing how much of the land use effect is 'lost' in traditional regional travel demand models.
| Project Timeframe | Start: 2000 | End: 2003 |
|---|---|---|
| Data Inputs | In addition to the usual travel model inputs this work requires multiple land use scenarios based on varying land use policies. The work may also require that the production and attraction balancing in the gravity model be reevaluated. | |
| Data Outputs | VMT, Congested VMT, Congested Speed, Transit Share, Motor Vehicle Emissions (VOC, CO, NOx) | |
| Sensitivity Analysis | Yes: three scenarios were compared. | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | Evaluated three land use strategies but did not implement controls. | |
The work on land use alternatives was done as a preliminary step in revising the MPO's long-range transportation plan. In the previous effort, the land use was fixed early in the planning process and several groups attacked the resulting plan because multiple land use patterns were not evaluated.
The MPO evaluated the effect of four growth patterns as part of their LRTP but did not vary density. The changes performed made a very small change in emissions of CO. The emissions analysis was based on network level statistics including VMT, and VHT. The modeling platform for this effort was EMME2.
Early in the long-range transportation plan update the MPO evaluated four possible land uses for their effect on travel and emissions. The land use patterns evaluated included a trend land use, a compact land use, a significantly sprawling land use, and a concentration of new development on large tracts of available land.
The evaluation discovered changes in travel, travel time, and emissions on the order of one percent between land use patterns. In part this may be due to the limited transit options available in Albuquerque to support higher density land use alternatives. While the model includes a predictive mode choice step only a fixed route bus mode was available at this point. An HOV mode has since been added to the model. The estimated change in CO was approximately 1 percent.
The project found that in the current model stream, whereby the travel model is disconnected from the emissions model, was not sensitive to changes on the scale that the land use alternatives presented. As a partial result of this exercise, the MPO has embarked on an ambitious model improvement program that involves creating a custom model in a GIS environment. This model allows much broader analysis of the data than did the earlier model.
| Project Timeframe | Start: September 2002 | End: January 2003 |
|---|---|---|
| Data Inputs | All standard travel model inputs | |
| Data Outputs | All standard travel model outputs | |
| Sensitivity Analysis | No | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | Evaluated four land use patterns but no additional controls. | |
Oregon's transportation planning rule (TPR) requires all cities to consider land uses when developing transportation plans. The City of Eugene Oregon has just completed this process for their current long range transportation plan.
The Eugene MPO has evaluated a series of integrated land use and transportation plans. The land use plans were selected to represent a range of variability based upon current policies. These policies ranged from no changes to extreme changes. For each land use plan a transportation plan was developed that supported that land use plan. Taken together the land use and transportation plans provided elected officials with a range of options that they could modify to meet the needs of the region.
Eugene evaluated a current trends scenario and five alternative plan concepts. In Eugene both land use measures and transportation measures were evaluated. The land use measures included a continuation of the existing land use plan. In this scenario growth is allocated evenly to developable land within the urban growth boundary. The other four land use scenarios are variations of a nodal development plan. In the nodal development concept a mix of land uses are developed in centers that support 1/4 mile walks to their commercial core and transit stops. The four nodal concepts are: development of nodes in all potential areas, development of nodes in new growth areas, development of nodes only in central areas, and development of nodes only along major transit (bus) routes.
In conjunction with the five land use plans, three transit systems and two highway systems were tested. The base transit system is a small expansion of the existing bus system intended to keep the bus system comparable with highway improvements. The enhanced transit system adds ten minute headways on major buss routes and twenty minute headways on service to nodal development areas. The bus rapid transit system builds upon the two lower service levels and provides eight radial routes and a circumferential route on exclusive right-of-way. In addition to the transit systems the MPO evaluated two highway systems (an existing plus committed system and an existing, committed, and planned network).
The results of the analysis described above are reported in a summary table comparing each of the alternatives evaluated with the existing situation and the base case with ten objectives listed. The six objectives are to minimize daily fuel use, minimize congested miles of travel, reduce per capita VMT, increase the number of person trips shorter than one mile, change the mode choice away from single occupant vehicle, and decrease motor vehicle emissions. Lane COG estimated emission reductions only for CO. In the four scenarios evaluated the change in CO emissions ranged from 4.5 percent for the scenario emphasizing land use changes to 26.6 percent for the scenario that meets Oregon's transportation planning goals. The CO reductions are 592 kg for the land use only scenario and 3650 kg for the planning goal scenario.
In staff's view the most difficult aspects of the process are political. Elected officials have differing opinions on planning and visions for the future. The most significant technical issue was a predictive model that could be used to evaluate the probable results of implementing a suite of land use, transportation, and pricing policies.
| Project Timeframe | Start: 1997 | End: 2001 |
|---|---|---|
| Data Inputs | All standard inputs for travel demand models and emission models. Multiple sets of land use. | |
| Data Outputs | Standard travel demand model outputs and emission model outputs that must then be formatted for easy understanding by elected officials. | |
| Sensitivity Analysis | Yes | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | No | |
The City of Charlotte participated in a USEPA grant program intended to assess the transportation and emissions effect of non-conventional development in urban areas. In Charlotte's case the original intent was to evaluate the effect of redeveloping existing industrial sites within the city limits.
In the brownfields redevelopment project MUMPO assessed the air quality benefit of concentrating additional development along proposed mass transit corridors within the City of Charlotte. Approximately 16,500 households were moved from the suburban fringe of Mecklenburg County into a proposed transit corridor south of Charlotte's city center. Travel and emissions were estimated for two land use scenarios and three transportation scenarios. Emissions and travel are both lower in the scenarios that redistribute growth into the corridor served by transit.
The MUMPO evaluated the emissions and travel effect of redistributing households and employment from the suburban fringe of Charlotte into a proposed light rail corridor south of the city center. MUMPO used their existing four-step travel demand model and MOBILE 6 to evaluate the travel and emissions effect of changes in land use and transportation networks caused by redeveloping brownfields near the proposed outh light rail corridor.
In the evaluation the land use in thirty-six traffic analysis zones along the LRT corridor were adjusted upward to reflect an additional 16,500 households and an additional 10,500 jobs. These jobs were taken from wedge areas outside the center city area so that the total housing and employment in Mecklenburg County was constant. Wedge areas are suburban fringe areas between proposed transit corridors for Mecklenburg County. The integrated land-use and transportation plan seeks to limit growth in wedge areas. The revised scenarios evaluated show emission savings of 1.3% for NOx, 1.6% for VOC, and 1.4% for CO which implies approximately 90 kg, 110 kg, and 1900 kg of daily emission reductions respectively.
The project contact noted no significant process or tool needs. He did note that using geographic information systems to analyze and reallocate data made the process much easier. In addition the MPO developed spreadsheet templates to manipulate MOBILE 6 output.
| Project Timeframe | Start: August 2002 | End: September 2003 |
|---|---|---|
| Data Inputs | Standard travel model parameters plus hand adjustments to socio-economic data for specific analysis zones and multiple transportation networks. | |
| Data Outputs | Trips, VMT, and emissions of VOC, NOx, and CO in kg. | |
| Sensitivity Analysis | Yes | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | No | |
The 2050 Blueprint Study is an outgrowth of a desire by the SACOG policy board to improve the integration of land use and transportation and to address perceived regional problems in a regional manner. There was some interest in improving the connection between land use planning and transportation planning beginning with the 1999-2001 update of the Long Range Transportation Plan but neither staff nor tools were available.
The 2050 Regional Blueprint is a 2-1/2 year integrated land use and transportation study for the Sacramento Council of Governments. Beginning in 2002 the study covered six counties in the Sacramento region and used the PLACES3 GIS package as a scenario builder. The 2050 Regional Blueprint is a multi-level land use and transportation study the evaluates the interaction of land use and transportation at the regional, county, and municipal levels. In each case both a trend land use and a smart growth land use are evaluated for a number of factors.
The 2050 Blueprint staff believes there are several things that can be done overall to improve the state of practice in integrating land use and transportation models. Keys to this effort are fully integrated travel and land use models. Important features of the integrated modeling package are tour based travel demand models and economically based land use models. In addition to the needed improvements to the travel and land use models the 2050 staff believe that emissions models should have sufficiently long time horizons to reasonably evaluate transportation scenarios more than thirty years into the future.
The 'Regional Blueprint' evaluated four land use scenarios: (A) existing trends, (B) growth focused at the edge of the region, (C) growth focused on the inner ring of suburbs, and (D) growth focused on the center of the region. Options B, C, and D reduce CO2 and fine particulates by 88 percent, 86, percent, and 85 percents respectively from Option A.
| Project Timeframe | Start: 2002 | End: 2004 (Final Phase) |
|---|---|---|
| Data Inputs | In addition to the usual travel model inputs this work requires multiple land use scenarios based on varying land use policies. The work was done in California so the emission model used was the EMFAC/BURDEN series. | |
| Data Outputs | Data outputs are vehicle miles of travel by mode, hours of travel, and speed, raw and adjusted link volumes, and emissions of CO, NOx, and ROG (aka VOC). | |
| Sensitivity Analysis | Yes | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | The transportation and emission effects of multiple land uses were evaluated. | |
This work was performed in the context of developing a long-range transportation plan, transportation conformity determination, and evaluating CMAQ projects. They have not done land use work down to the emissions estimation level that has gotten approval as a control measure. The agency's work is documented in the the 2020 Long-Range Transportation Plan and conformity appendix.
SANDAG has evaluated the travel and emissions effect of four different land-use scenarios. The four land-use scenarios are: (A) continuing existing policies, (B) locating the highest densities within 1000' of transit stations, (C) option B plus assuming that all future residential development occurs at that highest density permitted in the general plans and (D) option C plus a cap on residential development in unincorporated areas.
SANDAG uses a standard four-step travel demand model in the TRANPLAN platform. The model includes two iterations of congested speeds back into the trip distribution phase of the model to assure that congestion is correctly accounted for. SANDAG estimated emissions using EMFAC/Burden as required in California.
In the 2000 update of their long range transportation plan SANDAG has evaluated the travel and emissions effect of four different land-use scenarios. The four land-use scenarios are: (A) continuing existing policies, (B) locating the highest densities within 1000' of transit stations, (C) option B plus assuming that all future residential development occurs at that highest density permitted in the general plans and (D) option C plus a cap on residential development in unincorporated area. In addition to the land use measures studied the emissions analysis included the effects of new heavy duty diesel controls, an enhanced inspection and maintenance program, Federal and California 'M' measures for NOx and reactive organic compounds (aka hydrocarbons or VOC).
Implementing option D would result in emission reductions of 14.2%, 15.4%, and 11.2% for carbon monoxide, hydrocarbons (ROG), and oxides of nitrogen respectively relative to Option 1 or 50 kg, 6 kg, and 12 kg respectively.
The interagency consultation process for SANDAG includes SANDAG itself, APCD, Caltrans, CARB, USEPA, and USDOT. The interagency consultation process is strength of this study.
| Project Timeframe | Start: | End: 2000 |
|---|---|---|
| Data Inputs | In addition to the usual travel model inputs this work requires multiple land use scenarios based on varying land use policies. The work was done in California so the emission model used was the EMFAC/BURDEN series. | |
| Data Outputs | Data outputs are vehicle miles of travel by mode, hours of travel, and speed, raw and adjusted link volumes, and emissions of CO, NOx, and ROG (aka VOC). | |
| Sensitivity Analysis | The analysis may be considered a sensitivity analysis or a solution space. | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | No transportation control measures have been included in the SIP. | |
The Tri-County Regional Planning Commission is the Metropolitan Planning Organization of Lansing Michigan. It consists of 78 units of government of whom 50 have direct land use authority. The TCRCP is growing steadily and is consuming agricultural land at four times the rate of population growth. Development is occurring along existing arterials that are becoming stripped out. Local officials are concerned with preservation of open space and the cost of maintaining transportation and other infrastructure. Until recently the Tri-County area was attainment for all pollutants. It was declared nonattainment under the eight-hour ozone standard in April of 2004.
The project is a broadly scoped effort to implement performance based planning. The effort included up front stakeholder involvement to develop consensus, development of multiple land use scenarios, and evaluations of the impact on transportation, future budgets, and air quality. The project has been accepted by the many local governments with all 78 expected to approve the plan by fall of 2004. The plan is currently in the early phases of implementation.
The project involved multiple phases including stakeholder involvement, land use modeling, transportation modeling, and evaluation of consequences. Several of these efforts were prepared in parallel.
The stakeholder involvement process included five focus groups for citizens, interest groups and decision-makers. At the end of the stakeholder process over eighty percent of the participants agreed with the vision of community developed in the stakeholder process.
The formal analysis included the evaluation of four land-use and transportation scenarios. The scenarios are a trend land use, a build-out of the trend, a 'wise growth' scenario, and a build out of the 'wise growth' scenario. For the land use component the evaluation criteria included population accessibility to public services (parks, transit, sewer) and public expenditures on policing, fire protection, and EMS services. The transportation component was evaluated on transit ridership, deficient and near deficient VMT and VHT, and hours of delay. Emissions of ozone precursors and CO were also evaluated. At the 2025 design year emissions for all pollutant from the base case and the 'wise growth' case are essentially equal. In a build-out analysis that included an additional 912,500 people in the Tri-County area the 'wise growth' scenario reduced VOC emissions by 22 percent, CO emissions by 29.5 percent, and NOx emissions by 25% or approximately 11,130 kg, 72,500 kg, and 19,200 kg respectively.
At each phase of the evaluation the focus groups were asked to select their preferred alternative. Approximately 80 percent of respondents preferred the wise growth alternative.
The Tri-County alternative future project has entered the implementation phase with several municipalities adopting the land use maps and policies recommended in the project.
| Project Timeframe | Start: 1999 | End: 2004 |
|---|---|---|
| Data Inputs | Data inputs included existing and proposed land use, future land use and zoning rules. Travel modeling and emission modeling inputs are standard for the area. MOBILE 6 defaults may be used in this analysis. | |
| Data Outputs | Travel, Travel by mode, housing density/location, emissions, public sector costs, and motor vehicle emissions. | |
| Sensitivity Analysis | No | |
| Cost-Benefit Analysis | A Cost benefit analysis was used in conjunction with other factors to rank alternative futures. | |
| Land Use Control Strategies | A land use policy map that is used as part of project and site selection criteria. Commitments to co-locate or maximize the utility of public facilities. Transportation projects are screened against the area's land use map. | |
The Woodlands Town Center is a long term 'greenfield' development project with multiple public and private partners. The goal is to provide a large mixed use development north of Houston Texas (Montgomery County). The analysis of land use and emission was undertaken, in part, in an effort to justify funding of an integral trolley line and water taxi for congestion mitigation air quality funding. The Woodlands Town Center is a long term project that began in 1985 and has only recently come to fruition. Partners include the Woodlands Operating Company, The Brazos Transit District, The Goodman Corporation, Federal Transit Administration, Federal Highway Administration, Texas DOT, Woodlands Road Utility district, and Town Center Public Improvement District. The project has received both CMAQ funding and a STEP grant.
The Houston Region is expected to grow from a population of 1,000,000 to a population of 1,500,000 during the life of the project. The Woodlands development itself expects a build out population of 125,000 with 72,000 jobs and 2,750 employers. The private developers intend to plan for growth today to avoid remedial infrastructure work later; de-emphasize the automobile as the mode of transportation; provide alternative modes of transportation to address transportation needs; and link major destinations along the corridor to adjacent development.
The benefits of this approach are enhanced mobility, reduced parking ratios, reduced air pollution, increased land values, economic growth, and a viable downtown.
Trips associated with the Woodlands Town Center were estimated by construction phase using the ITE Trip Generation Manual. Once the land use was turned into trips design elements and the transit system were sized to accommodate a high percentage of the internal trips. A trolley and water taxi system was sized to capture both peak period trips and event traffic from hotels and a convention center. The site design anticipates eliminating 6,500 vehicle trips a day along with 13,000 kg of VOC, 4,800 kg of NOx, and 102,000 kg of CO per day.
A key need for this type project is accepted methodologies to evaluate the transportation and emissions differences between urban and suburban development patterns. Both travels model and the emission models are scaled to regional level analysis.
| Project Timeframe | Start: 1989 | End: 2000 |
|---|---|---|
| Data Inputs | Site plan and parcel level land use data. | |
| Data Outputs | Annual trips, daily trips, transit passengers, VMT savings, emissions savings, and energy savings. | |
| Sensitivity Analysis | No | |
| Cost-Benefit Analysis | No | |
| Land Use Control Strategies | Yes, included in the Texas SIP | |
1 Note: While this case study has been used to show the use of the travel demand model and emissions model to determine the impacts of development on different locations within a growing urbanized area, areas should not consider this a model for TCMS. While portions of this project do meet the traditional TCM definition, the 17th Street bridge and freeway ramps would not qualify as a TCM without the Project XL designation.
