Colorado updates transportation plans to comply with new climate rules

Last month, Colorado’s transportation planning agencies officially updated their plans and project lists to meet the Colorado Department of Transportation's (CDOT) new greenhouse gas (GHG) reduction targets. The new plans spend significantly less money on highway expansions and redirect billions of dollars toward multimodal projects like transit, biking, and walking infrastructure to make these low-carbon transportation options more convenient, safe, and affordable for Coloradans. By giving people more choices and supporting more transportation-efficient land use patterns, the updated plans are expected to reduce total driving, or Vehicle Miles Traveled (VMT), by 6-9% in 2030, up to 850 fewer miles of driving for the average Coloradan every year.

This is a notable transition for CDOT and a clear departure from the traditional approach to transportation planning. Over the last 70 years, the United States has spent the vast majority of transportation funds on costly highway expansions and other car-centric infrastructure, creating a reinforcing feedback loop of car-dependence, more traffic, and worsening air pollution. As a result, Americans drive about twice as much as people in other industrialized countries and transportation is now the highest-polluting sector of the nation's economy. 

A recent GHG progress report to Colorado’s Air Quality Control Commission highlighted the state’s struggle to decarbonize transportation, anticipating little to no progress in GHG reductions from 2020 to 2025. In 2021, Colorado’s transportation sector produced 32% more carbon dioxide pollution than the state had anticipated, around 33 million metric tons (MMT) when the projection was 25 MMT (see table below). Meanwhile, Colorado is counting on a 40% reduction in transportation emissions, down to 18 MMT by 2030, to meet the statutory state climate targets set in House Bill (HB) 19-1261.

Figure 1: Transportation GHG Targets and Reported Emissions (million metric tons of CO2e per year). Source: Colorado Air Pollution Control Division’s Greenhouse Gas Reduction Goals Progress Report to Air Quality Control Commission (August 2022), SWEEP.

Q: How do we cut transportation GHG pollution? A: Reduce consumption of polluting fuels

1. Electrify all cars, trucks, and buses on the road and fuel them with clean electricity;
2. Build a connected multimodal transportation system with safe, affordable, and reliable infrastructure for transit, biking, and walking to give people low-carbon alternatives to driving;
3. Develop smart land use policies that put housing closer to jobs and other services to reduce driving trips and distances; and 
4. Reduce spending on highway expansions and interchange projects that increase VMT and GHGs through induced demand and by enabling sprawl.

Electric vehicles (EVs) are essential to meeting our transportation climate targets, but insufficient on their own to cut emissions fast enough. According to state modeling, an optimistic EV adoption scenario where we go from 60,000 EVs in 2022 to 940,000 in 2030 (about 17% of all vehicles on the road), is expected to get Colorado about 55% of the way to our 2030 transportation GHG target (red, yellow, green, and orange wedges in Figure 2). This assumes Colorado takes action to adopt Advanced Clean Cars 2, Advanced Clean Truck, and Heavy-Duty Omnibus rules requiring manufacturers to sell cleaner vehicles. Given that level of EV deployment, the remaining 45% of the total needed emission reductions (blue and teal wedges) must come from reductions in total driving, or VMT.

Figure 2: Progress toward Colorado’s 2030 transportation GHG targets by policy category.

The GHG Planning Standard is Colorado’s first concerted and coordinated effort to tackle VMT. To be clear, the policy is less about making it difficult to drive and more about making it easier to take other modes of transportation by leveling the playing field. Most people drive because it’s the most convenient, fastest, and in some cases, only way to get around. This is a policy choice reinforced by decades of investment in projects that move cars more quickly instead of moving people more efficiently, safely, and equitably. 

We must now make a new policy choice to rectify the negative impacts of highway expansion and align future spending with our environmental and social goals. While not perfect, (especially since it’s the first of its kind in the U.S.), CDOT's new Planning Standard is a significant step in that direction. 

The new standard is especially timely given the passage of the federal Infrastructure Investment and Jobs Act of 2021 (IIJA), which increased Colorado’s state transportation budget by over 34% with almost no strings attached, essentially silent on the climate front for the bulk of funding. Modeling shows that investments from the IIJA can either increase GHG emissions by 1.6% or decrease them by 1.3% depending on how states and local governments decide to spend the money. 

Additionally, around 30% of the total transportation funds in the IIJA, or $200 billion over five years, will be awarded by the U.S. Department of Transportation through competitive grant programs with a focus on environment, safety, and equity. Colorado’s decision to prioritize climate-friendly transportation projects can attract more federal investment to our state and help us meet our climate, air quality, safety, and equity goals. 

What is the CDOT GHG Planning Standard and how does it work?

The origins of CDOT’s Planning Standard date back to Colorado’s 2021 GHG Pollution Reduction Roadmap, which includes sector-specific GHG reduction targets and a list of near-term policies to meet those targets. Subsequent legislation, Senate Bill (SB) 21-260, directed CDOT to establish GHG reduction targets for state and regional transportation plans with a compliance deadline of October 1, 2022. 

Similar policies exist in other states like California and Massachusetts, but haven’t been very effective because they lack strong enforcement. Unlike other climate policies that Colorado has copied or borrowed from other states, like the Zero-Emission Vehicle Standard, EV tax credits, and Renewable Portfolio Standards, the transportation GHG rule was mostly developed from scratch by CDOT, regional agencies, and other stakeholders. 

In August of 2021, environmental and transportation policy advocates created a checklist to evaluate the CDOT’s proposed rule based on whether it could be expected to deliver on coalition priorities to expand multimodal transportation options, benefit Disproportionately Impacted Communities (DICs), effectively reduce GHG emissions, and more. (See the full checklist here.)

Structure of the rule:

Step 1: Measuring the baseline
The GHG Planning Standard requires CDOT and the Metropolitan Planning Organizations (MPOs), the regional planning agencies in Colorado's five largest urban areas, to model the GHG impacts of their existing transportation plans for target years 2025, 2030, 2040, and 2050. This baseline is an estimate of how much additional GHG pollution our planned investments can be expected to generate in those horizon years. CDOT and the Denver Regional Council of Governments (DRCOG) have very sophisticated travel demand models to monitor our system and predict future needs. Think of it like a giant SimCity model with all the roads and buildings in our state and travel attributes that respond to planned transportation investments and other factors.

Step 2: Update transportations plans
CDOT and MPOs must update their plans to comply with the GHG reduction targets for each horizon year. The targets are based on each region’s share of the state population. For example, the 2030 GHG reduction target for DRCOG, the nine-county Denver metro area, is 820,000 metric tons, a 9% reduction from the baseline plan. To comply with the rule, DRCOG had to shift investments away from projects that increase GHGs and toward projects that lower emissions until they hit the target.

Table 1: GHG Transportation Planning Reduction Levels in MMT of CO2 (Source: CDOT Rules Governing Statewide Transportation Planning Process and Transportation Planning Regions)

For 2025, the first compliance year, the targets only apply to DRCOG, the Northern Front Range MPO (NFRMPO), and CDOT projects in the non-urbanized areas because those agencies have advanced air quality modeling capabilities from years of ozone planning along the Front Range. The remaining three MPOs in the Colorado Springs, Pueblo, and Grand Junction metro areas were given until 2030 to comply since they are still developing their modeling capabilities, hence the “N/A” for 2025 reduction levels.

Step 3: Contingency plan (GHG Mitigation Action Plan)
If the updated model falls short of the GHG reduction targets in Step 2, CDOT and MPOs must create a complementary “GHG Mitigation Action Plan” to close the gap with a series of smaller, nontraditional “off model” strategies like sidewalks, bike lanes, and electric buses, as well as changes to the built environment, like transit-oriented development, residential infill, and reduced parking requirements in new buildings. These strategies have the potential to reduce GHG emissions, but are not typically represented in the larger transportation models, so CDOT created a separate compliance document for them called the GHG Mitigation Action Plan.

One of the most important achievements of the rule is that we now have a better idea of the climate impacts of our transportation investments and can use the GHG formulas in CDOT’s Policy Directive 1610 to compare the GHG savings of different projects. For example, one mile of bike lane in an urban area is expected to reduce GHG emissions by 23 metric tons per year. Adding 1,000 new hours of transit service with an electric bus would cut 27 metric tons per year. (See the full list here starting on page 13.)

DRCOG was able to get 80% of the way to their 2030 GHG target by updating their transportation plan (Step 2) and they used a GHG Mitigation Action Plan (Step 3) for the remaining 20%. For CDOT, those percentages were about 60% and 40%, respectively. NFRMPO was able to achieve 100% of the 2030 GHG targets through their plan update and therefore, didn’t need to submit a GHG Mitigation Action Plan.

Putting it all together

Table 2: Summary of 2030 GHG Compliance for DRCOG

How is the GHG Planning Standard enforced?

A policy’s efficacy is only as strong as its enforcement and one of the Planning Standard’s strengths is that it has some teeth. If CDOT falls short of the GHG targets, the agency must award a larger percentage of its 10-Year-Plan funds to projects that reduce pollution. Similarly, MPOs are required to allocate funding from federal programs like the Surface Transportation Block Grant and Congestion Mitigation and Air Quality programs to projects that cut emissions or else CDOT has the authority to redirect those funds itself. This sends a clear message to MPOs and local governments that if they want to maintain control of their funding, they need to comply with the GHG reduction targets. 

The bountiful co-benefits of VMT reduction

Climate change is reason enough to shift our transportation investments, but there are plenty of other reasons to prioritize VMT reduction strategies. In 2021, CDOT published a Cost-Benefit Analysis of the Planning Standard, finding that Coloradans could save over $40 billion by 2050 from driving less.

Figure 3: Economic Benefits (Cost Savings) of CDOT’s proposal GHG Planning Standard (Source: Cost-Benefit Analysis for Rules Governing Statewide Transportation Planning, SWEEP).

In other words, this isn’t just about avoiding climate disasters, it’s also about building a better transportation system that saves lives, protects public health, saves people money, and improves access to opportunity whether you drive a car or not. This is particularly important for the 20-40% of Coloradans who don’t drive, either because they’re too young, are older adults, have a disability, or simply cannot afford a car, the most expensive transportation option. A world built exclusively for cars severely restricts access to jobs and other opportunities for many Coloradans.

VMT reduction is a simple and effective way to meet our climate targets while maximizing the potential social benefits of the policy. For this reason, states like Minnesota, Washington, and California have set VMT reduction targets for 2030 and 2050. Despite calls from advocates, the Colorado GHG Planning Standard does not set enforceable VMT reduction targets, but the list of allowable GHG mitigation strategies is heavily geared toward VMT reduction. 

For example, the Planning Standard doesn’t include vehicle technologies like EVs on the list of GHG mitigation strategies since the rate of EV adoption is largely unaffected by transportation planning. EVs are a critical piece of the climate puzzle, but the state has other important policies to accelerate transportation electrification, like the Zero-Emission Vehicle Standard, EV tax credits, and charging infrastructure investments, not to mention the half a trillion dollars of investment from automakers in EV innovation and manufacturing — private sector support that isn’t available for non-auto transportation options like transit, biking, and walking.

Has the GHG Planning Standard really made a difference?

The good, the bad, and the questionable:

In its first implementation cycle, the rule shifted billions of dollars worth of transportation funding toward climate-friendly projects, a big win for Coloradans. For example, DRCOG’s updated plan directs $2.2 billion of the $15 billion total to projects that reduce GHG emissions. 

Based on the reporting, the majority of the GHG reductions are achieved by removing highway expansions, maintaining high levels of telework, and encouraging changes to local land use and parking policies to create more transportation-efficient communities. Other strategies like Bus Rapid Transit (BRT), bicycle and pedestrian infrastructure, Transportation Demand Management programs, bus electrification, Bustang expansion (CDOT’s intercity transit service), and roundabouts play a supportive role, but together represent less than 10% of the total 2030 GHG reductions for CDOT and DRCOG.

The good:

Less highway expansion: Real-world data shows that highway widening leads to more traffic and pollution, and state DOTs around the country are grappling with the fact that we cannot build our way out of congestion (see Houston’s 26-lane Katy Freeway). California’s Department of Transportation, the operator of the nation’s second largest highway network, recently released an infographic to illustrate the cycle, declaring “there’s got to be a better way.”

Figure 4: Caltrans’ “Rethinking How We Build So Californians Can Drive Less” Infographic.

Highway widenings also represent a significant opportunity cost. Colorado has spent tens of billions of dollars on highway expansion projects that could’ve been better spent on demand-side strategies that optimize the use of existing road capacity and don’t require the bulldozing of our communities for more lanes of traffic. The updated plans:

• Cancel highway expansions on I-25 through central Denver and C-470. The $1.5 billion I-25 widening would’ve increased VMT by 70 million miles per year, about the same as adding 5,600 passenger cars and light trucks to the road each year. It also would’ve demolished neighborhoods and introduced more air pollution to communities already suffering from some of the worst air quality in the state in the Sun Valley and Valverde neighborhoods.
• Replace road widenings with complete streets: DRCOG adjusted the scopes of seven big road projects to refocus on safety and multimodal improvements like bike lanes and sidewalks instead of widening those roads to six lanes of vehicle traffic. 

Accelerated transit projects:

• Five new BRT corridors completed by 2030 on Colfax Ave, Federal Blvd, Colorado Blvd, State Highway 119, and East Colfax Ave. Upgrading these corridors with transit-priority lanes and more frequent and reliable service is expected to increase daily ridership by 68%. DRCOG also upgraded the Broadway/Lincoln BRT project to the 2030-39 time frame. New BRT corridors on Colfax Ave, Colorado Blvd, and Federal Blvd will reduce annual VMT by 67 million miles, nearly the same GHG savings as canceling the expansion of I-25 Central. Importantly, these corridors will improve equity by lowering transportation costs and expanding access to jobs for residents of disproportionately impacted communities, many of whom are transit-dependent. 
• Expanded Bustang Service: With $30 million in new funding from SB22-180, CDOT is poised to double Bustang service on I-25 between Colorado Springs and Fort Collins and more than triple service along I-70 between Denver and Grand Junction, attracting 51,000 more riders by 2030. 
• Regional Transit in Northern Colorado: The NFRMPO pledged an additional $147 million to improve transit service between Loveland and Greeley, expand local transit in Loveland, and work with CDOT to expand Bustang service and develop mobility hubs along I-25. As a result, total transit trips are expected to increase by 17% in the region by 2030.

Prioritized active transportation projects:

• SB21-260 replenished the Multimodal Transportation and Mitigation Options Funds and created a new Revitalizing Main Streets program to support bicycle and pedestrian infrastructure projects in downtown areas around the state. These planned investments, combined with local and state eBike incentives, are expected to improve the safety, comfort, and convenience of walking and biking, increasing their share of total trips.
• DRCOG plans to spend an additional $900 million on multimodal transportation infrastructure by 2050 ($500 million by 2030) on seven key corridors in the region, as well as upgrades to the South Platte River Trail, one of the most heavily used bicycle and pedestrian paths in the region. 
• The NFRMPO is committing an additional $283 million to expand its bicycle and pedestrian network and support the adoption of eBikes and scooters.

Table 3: Model Outputs and Trips by Mode in 2030 for Baseline & Updated Plans.

The bad: CDOT postpones important equity provisions

The final rule acknowledges the fact that DICs, often lower-income neighborhoods and communities of color in urban and industrial areas, are exposed to higher levels of dangerous air pollution and have limited access to safe and affordable transportation options like walking, biking, and transit. DICs near urban highways have a higher risk of childhood asthma, reduced lung function, and cardiovascular issues leading to high healthcare costs and poor educational outcomes. In addition, low-income households experience a higher transportation cost burden, spending about one-third of their income on transportation, almost twice as much as middle-income households. Our transportation policies have reinforced these economic, social, and health disparities, but they also have the potential to rectify them. 

The rule references Colorado’s Environmental Justice Act (HB21-1261), which states “less-burdened communities have benefitted from relationships that impose burdens on other communities, which is a tangible debt that must be repaid through financial reinvestment,” a recognition that we must now affirmatively further clean transportation access in DICs to address racial and economic inequality. 

In the final rule, CDOT commits to: 

• Working more closely with community groups to develop transportation projects, 
• Measuring the impact of transportation investments on equity, and 
• Prioritizing projects that directly benefit DICs in the GHG Mitigation Action Plans. 

Importantly, CDOT will consider the “geographic nexus” of transportation impacts to avoid dumping new pollution into DICs (sometimes referred to as “sacrifice zones”) and cleaning it up in other, most distant communities around the state. In other words, the pollution offsets for transportation infrastructure projects should be located in the same community to directly benefit nearby residents. While this may “soften the blow,” many advocates argue that we should stop widening highways through DICs altogether and instead redirect those funds to projects that benefit the local community rather than prioritizing suburban through-traffic. 

At one point, CDOT committed to developing an “equity multiplier” to boost the scores of transportation projects that both reduce GHG emissions and benefit DICs, but the idea was abandoned because 1) CDOT wasn’t sure how to measure equity, and 2) the agency didn’t want to artificially inflate the GHG values of transportation projects in the context of the rule.

In the end, CDOT wasn’t able to develop an equity framework in time to influence the updated plans. The equity provisions were supposed to be considered in a May policy decision, but were postponed to December because they weren’t ready for primetime — a disappointing outcome that reinforces the “equity as an afterthought” narrative in state policymaking. However, the agency does appear to be making progress under the leadership of its new Equity Director and with a more robust and inclusive community engagement process. 

The questionable: Unsecured climate benefits from telework and voluntary land use strategies

Any successful climate rule should deliver GHG reductions that are “real, additional, quantifiable, permanent, verifiable, and enforceable.” The state’s Department of Public Health & Environment committed to those criteria in 2021 alongside a promise to avoid adding new pollution to DICs. This is the sniff test we should be using to determine the efficacy of individual climate policies.

Neither CDOT nor DRCOG were able to meet the 2030 GHG targets by simply reshuffling their transportation project list (Step 2 described above), so they developed a Mitigation Action Plans (Step 3) to close the gap, which for DRCOG was about 12% of the target and 41% for CDOT. 

Both agencies rely heavily on land use strategies to reduce GHGs through increased residential and job density, and more mixed-use Transit-Oriented Development. DRCOG’s land use analysis identifies the best candidates for redevelopment near transit and in pedestrian-oriented zones, then assumes a subset of those would be rezoned by local governments and redeveloped by 2030. The total land area is 1,379 acres (2.15 square miles) and the GHG reductions from rezoning would be the equivalent of taking 9,200 cars off the road. For reference, 2.15 square miles represents two-tenths of one percent of the DRCOG total territory, which demonstrates the potency of land use as a climate strategy. 

In fact, the University of California, Berkeley's local government climate tool shows that infill development is one of the most impactful things local governments can do to combat climate change (Figure 5). When it comes to public transit, over 80% of the climate benefits are from more efficient land use around the transit stations with compact, mixed-use development reducing the number and distance of car trips and enabling more biking and walking. Achieving a modest level of compact development in every American city has the same emissions reduction potential of every state in the US adopting a 100% EV sales target by 2035.

Figure 5: The University of California, Berkeley's California Local Government Climate Policy Tool quantifies the potential of local policies to meet GHG reduction targets. The chart above ranks the most impactful climate strategies for the City of Sacramento, with “urban infill” at the top. Infill development consistently ranks at or near the top for all of the 800 cities and counties analyzed.

DRCOG relies on parking reform for another 7% of the 2030 GHG target. Cities across the country have been overbuilding on parking and underproducing on housing for decades, one reason the U.S. has eight parking spaces for every car, but is 3.8 million homes short of a stable housing market. Reducing or eliminating minimum parking requirements and replacing them with maximum levels for new residential and commercial buildings could cut 60,455 MT of GHGs by 2030, the equivalent of taking 13,000 cars off the road.

All of this is encouraging except for the fact that neither DRCOG nor CDOT have any authority over local land use decisions. Zoning regulations that dictate the size, type, and location of development are exclusively in the hands of local governments. Without a firm commitment from local governments to upzone around transit stations or increase the density of housing and jobs in urban areas, the claimed GHG savings are completely hypothetical. They’re wishful thinking. 

This piece automatically fails the sniff test since the GHG reductions are neither real nor enforceable. To fully implement the rule and satisfy its intent, CDOT and MPOs should work closely with local governments to update their land use and zoning regulations to support more transportation-efficient development. MPOs can offer technical and planning assistance to help local governments evaluate potential zoning reforms and understand the full impacts of land use changes. CDOT and MPOs should also revise their policy guidelines to align transportation funding with efficient land use. For example, agencies should offer transportation funds to build street connections, bike lanes, and sidewalks around infill development projects to accelerate and lower the costs of their construction. Less financial support should be available for less transportation-efficient development types that have negative environmental and social impacts, and increase pollution, congestion, land and water consumption, and transportation costs.

The rule requires CDOT and MPOs to track and report their progress on the GHG mitigation measures like land use strategies. If these voluntary strategies haven’t been secured through zoning reform in the next year, agencies should find a way to compensate and revisit their plans to ensure the resulting GHG reductions are “real, additional, quantifiable, permanent, verifiable, and enforceable.”

Optimistic modeling assumptions

Second, transportation agencies rely heavily on telework to reduce GHG emissions when the jury is out on the efficacy of this strategy to reduce VMT or GHGs. Agencies doubled or tripled their telework assumptions to reflect recent changes in commuting and work-from-home trends.

Table 4: Updated telework assumptions by agency. (Source: SWEEP)

If telework did have a meaningful impact on driving, VMT in 2021 would be significantly lower than 2019, the year before the pandemic. However, total VMT in the U.S. through the first half of 2022 was just 0.64% below the total for the first half of 2019 with three of the six monthly totals exceeding 2019 levels.

Studies show that, contrary to CDOT’s modeling assumptions, telecommuting may actually increase total driving and emissions. Telecommuters may not drive to work, but they do still drive to the grocery store, doctor’s appointments, to drop their kids off at school, go to the gym, and reach other destinations — trips they may have previously bundled with commuting. Others may have moved further away from urban job centers and into more dispersed, higher-VMT communities in more rural areas. Some may have bought a car in the early days of the COVID pandemic to replace transit and never looked back. The point is that we don’t fully know the long-term impacts of these relatively recent transportation trends, so it’s risky to rely on them to meet our climate targets. 

It’s worth noting that while VMT has returned to pre-pandemic levels, traffic congestion has decreased significantly due to shifts in travel times away from peak “rush hour” periods and toward different times of the day. Given this trend, transportation planners should reconsider the need for new highway lanes to accommodate peak demand during rush hour.

Additionality: How much of these GHG savings are additional and wouldn’t occur without the rule? 

Much of compliance process seemed like an exercise in tracking clean transportation investments that were already secured, like the state’s SB21-260 MMOF program, Revitalizing Main Streets grants, and SB22-180 Bustang investments, as well as trends that were already underway with or without transportation plan updates, like telework and higher-density development in the Denver region. All three agencies were able to ride the coattails of increased telework to claim more GHG savings, a trend that was in motion before the rule and has questionable climate value. A stronger climate policy would secure GHG reductions that would not have otherwise occurred without the policy. In other words, each metric ton of avoided GHG emissions should be directly linked to a project modification or funding decision.

Colorado needs a more transformational level of investment in transit, biking, and walking

Even with the 1.5 MMT reduction from the GHG Planning Standard and all the vehicle electrification policies and incentives in Colorado, we’re still about 35% shy of our 2030 transportation GHG target suggesting we need a deeper level of VMT reduction. The Planning Standard redirects a significant amount of money to multimodal projects, but it’s not enough to be transformative. 

For example, DRCOG’s updated plan is expected to reduce the share of trips taken in a car from 87% to 82% in 2030, a commendable reduction, but still higher than peer cities like Portland (77%), Seattle (75%), and San Francisco (64%). The bulk of our transportation dollars are still going to new highway lanes on I-25 North, I-70 near Floyd Hill, and I-270 in North Denver. To meet our 2030 climate targets and maximize the social benefits of VMT reduction, we need to go bigger on transit, biking, and walking by prioritizing the rapid and equitable build-out of a safe and connected multimodal network.

Figure 6: Impact of GHG Planning Standard on Mode Share in DRCOG region by 2030. (Source: SWEEP)

How to make the GHG Planning Standard more effective

The Planning Standard is a promising start to climate-friendly transportation planning, though there’s plenty of room for improvement in its implementation and tracking. To make the policy more effective, CDOT should consider:

1. Continuous improvements to the modeling. Periodically review the modeling assumptions by comparing forecasts to real-world data, and update the models and plans accordingly. CDOT and MPOs should take steps to incorporate “off model” GHG mitigation strategies like land use into their travel demand models to simplify the compliance process.
2. Make all compliance and GHG mitigation strategies mandatory instead of voluntary to secure real and additional GHG reductions from the rule. For example, to receive credit for strategies in the GHG Mitigation Action Plan like land use and parking policies, agencies must prove they had a direct role in securing a firm commitment from local governments to implement those policies. 
3. Replace the GHG targets with VMT reduction targets to simplify implementation, maximize the co-benefits, and avoid reliance on dubious GHG reduction strategies like traffic operations improvements, roundabouts, ramp metering, and traffic signal synchronization. Instead of assuming that VMT will inevitably grow and building new highway lanes to accommodate more vehicle traffic (a self-fulfilling prophecy because of induced demand), agencies should assume VMT will decrease in line with targets and make the necessary investments to meet those targets.
4. Increase the stringency of the targets. Consider increasing the 2030 target from 1.5 to 3.2 MMT to close the remaining gap and reduce transportation GHG emissions 40% by 2030.
5. Require agencies to demonstrate a direct connection between plan updates and GHG reductions. The Planning Standard should only count GHG reductions that would not have otherwise occurred without the rule. In other words, each metric ton of avoided GHG emissions should be linked to a plan update or project modification. 
6. Develop an Transportation Equity Index to measure the impact of transportation investments on DICs and prioritize projects that deliver direct benefits. Do this for all transportation projects, not just those in the GHG mitigation action plan. Develop a meaningful community engagement process with DICs to develop transportation equity metrics and community-driven transportation projects. 
7. Require local governments to do their part. The Planning Standard sets GHG reduction targets for CDOT and MPO plans, but not local governments, creating implementation challenges at the regional level. Meeting our climate targets will require an “all hands on deck” approach from all levels of government. This year, cities and counties will receive roughly $360 million from the state’s Highway Users Tax Fund, the revenue collected from vehicle registration fees and gas taxes. The Planning Standard should require local governments to use those funds in ways that help Colorado meet our climate targets. 
8. Explore strategies that adjust the price of driving to accurately reflect its social and environmental costs. CDOT’s list of allowable GHG mitigation measures should include strategies that ensure driving pays its way, e.g., through parking and congestion pricing, and use the revenue to improve alternatives to driving. These strategies have enormous potential to reduce GHG emissions. 
9. Expand its scope to include privatized highways in the GHG calculations. Expanding toll roads like E-470 will have an impact on transportation emissions, so they should be included in GHG planning.

Additionally, now that their plans are updated, CDOT and MPOs need to develop complementary policies to successfully execute their vision and support the rapid expansion of multimodal transportation infrastructure, including: 

1. Streamline transit, bicycle, and pedestrian infrastructure projects. Accelerate the designing, permitting, and construction of non-auto transportation infrastructure like BRT. When it’s completed in 2028, the Colfax BRT project will have taken 14 years to plan, design, and build. Moving forward, we must find ways to accelerate these project timelines, especially if we hope to complete four more BRT projects by 2030 and the other six in DRCOG’s priority BRT list by 2040.
2. Update project scoring criteria to prioritize transportation projects that facilitate more efficient land use and help lower the cost of infill development. For example, DRCOG should update its Transportation Improvement Program policy to reward projects that support transportation-efficient land use (e.g., bicycle and pedestrian connections in compact, mixed use communities).
3. Directly fund local and regional transit service to improve frequency and reliability. Along with transit-supportive land use, better service is the most effective way to increase transit ridership.
4. Leverage federal competitive grant programs to meet climate goals. Partner with advocates and community-based organizations to attract more federal funding to Colorado for multimodal transportation projects. 
5. Stop expanding urban highways, especially in DICs. Require regionally significant projects in DICs to, at the very least, “do no harm.”
6. Take Vision Zero seriously and transform the most dangerous urban arterials to Complete Streets immediately. The lack of safe and connected bicycle and pedestrian infrastructure along these corridors deters walking and biking, divides communities, and limits the economic potential of main streets. Coloradans won’t walk or bike if those modes are life-threatening. Agencies need to make safety a top priority to provide viable alternatives to driving.
7. Convert existing lanes to managed lanes instead of building new ones. Instead of spending billions of dollars adding new highway lanes through urban communities, transform existing general purpose lanes into managed lanes for buses, carpooling, and tolls, and use the toll revenue to fund more efficient modes.
8. Separate multimodal improvements from road widening. Oftentimes, agencies bundle new bicycle and pedestrian infrastructure with road widenings, which delays projects and undermines walking and biking. Communities shouldn’t have to wait years to get sidewalks and bike lanes.

Conclusion

All in all, the GHG Planning Standard will have a positive impact on our transportation system, prompting investments that not only reduce GHG emissions, but also improve safety, lower transportation costs, advance equity, and increase mobility and access to opportunity for Coloradans, especially those who don’t drive. The rule builds in plenty of checkpoints and reporting requirements along the way to measure our progress and improve its efficacy for future planning cycles. We also commend CDOT for hosting a welcoming and inclusive stakeholder engagement process. The rulemaking process was informative and eye-opening for advocates, planners, and elected officials, and will inevitably leave a lasting mark on our approach to transportation planning. We look forward to partnering with CDOT, MPOs, and other stakeholders in continuing to fine-tune the rule and its implementation to maximize its effectiveness. Lastly, we encourage other states to follow Colorado’s lead in adopting similar policies to reduce their transportation-induced climate pollution.