Caltrans unveils draft California Transportation Plan update; modeling approach prompts pushback from stakeholders

Caltrans on Wednesday outlined its draft update to the California Transportation Plan, saying the document will use a 20‑year planning horizon and a revised modeling approach intended to show what is "feasibly" likely to happen and what additional strategies and investments would be required to meet the state's greenhouse gas and vehicle‑miles‑traveled (VMT) targets.

Hannah Walter, Deputy Division Chief for the Caltrans Division of Transportation Planning, told the three‑agency joint meeting that "the California Transportation Plan is required by state and federal law. We have to update it every five years. It has a 20‑year planning horizon," and that the update will focus on three central topics: greenhouse gas reduction goals, VMT reduction goals and closing the transportation funding gap. "For this update in particular … we really wanted to focus on what is a feasible estimate of future conditions, and what are meaningful steps that we could take to try to achieve our greenhouse gas reduction and VMT reduction goals," Walter said.

Caltrans said it used an updated statewide travel‑demand model to estimate likely future conditions through 2050 and then to test suites of strategies — including transit, bike‑ped investments and pricing — to show the trade‑offs and costs of moving from that projected future to an outcome that meets statutory targets. The agency aims to release a draft for public comment in July and complete final approvals by December to meet statutory timing.

Stakeholders who serve on advisory committees or represent regional planning agencies raised concerns about the new modeling approach. Greg McIntyre of the California Association of Councils of Governments said he supported "the more realistic fiscal data and planning assumptions being used in the travel‑demand model," arguing realism helps produce implementable policies. In contrast, Sofia Ravikova of the Coalition for Clean Air — who also serves on Caltrans’ Policy Advisory Committee — said the committee "overwhelmingly promoted strategies that would reduce vehicle miles traveled" and warned the updated model "labels them as less effective" because it favors a realism standard over the statutory directive to consider how the state will achieve "maximum feasible emissions reductions." She urged Caltrans to update the model so it better reflects statutory requirements and gives advisory members adequate time to respond.

Caltrans staff responded that the intent of the update is not to retreat from the state's VMT and greenhouse‑gas goals but to provide a clearer accounting of what will be required to reach them. "We're 100% trying to support the VMT and GHG reduction goals with this plan," Walter said. She described the approach as a two‑step technical exercise: first, estimate a feasible future given current policy and trends; second, model what combinations of strategies would be required to close the gap to the statutory targets, and at what cost.

The draft plan will include proposed performance measures, a fiscal analysis required under recently enacted state law, and a housing chapter that Caltrans said was informed by HCD comments. Commissioners at the meeting asked Caltrans to strengthen the plan’s discussion of infill housing and its role in meeting VMT targets and to coordinate closely with CARB and HCD on VMT assumptions.

Caltrans officials said the plan will include recommended metrics and an implementation dashboard to allow tracking of progress against goals, but added they will not be able to go to project‑level impact analysis for every community in a single statewide document. The agency emphasized that the CTP is one part of a larger set of regional and state planning processes, and invited additional briefings and a 45‑day public comment period once the draft is published.

The discussion underscored a recurring tension in statewide planning: whether to model aggressive, legally framed targets as feasible actions to be achieved, or to first present a technically grounded estimate of what current trends will produce and then identify the additional policies needed to reach the statutory objectives. Caltrans framed the update as intended to make those trade‑offs explicit to policymakers and the public.