Sonoma–Marin Area Rail Transit (SMART; ) is a commuter rail service and bicycle–pedestrian pathway project in Sonoma and Marin counties of the U.S. state of California. When fully built, the system will span a corridor between Cloverdale in northern Sonoma County and Larkspur Landing in Marin County. In , SMART recorded an annual ridership of , averaging about weekday passengers as of .
The segment between and opened for preview and excursion service on June 29, 2017. The full first phase, running between and , began regular service on August 25, 2017, following Federal Railroad Administration approval of the line's positive train control system. Service was extended south to on December 14, 2019, and north to station on May 31, 2025. A extension to is under construction, with completion expected in 2028, while the final extension north to remains planned but unfunded.
The district is funded primarily by Measure Q, a quarter-cent sales tax approved by voters in November 2008 that expires in 2029. Revenue fell short of projections during the Great Recession, requiring phased construction. A citizen-led initiative qualified a 30-year sales tax extension for the June 2026 ballot.
History Background and formation The last passenger rail service along the Northwestern Pacific Railroad south of Willits was discontinued in 1958 as automobile travel along U.S. Route 101 in California increased in popularity.
The SMART District was formally established by state legislation (Assembly Bill 2224) in 2002, which mandated the district's creation and established its governance structure across the two counties. Previously disused station buildings were repaired in anticipation of reestablished rail service in Healdsburg and Windsor, and Cloverdale's depot was constructed in 1998.
Environmental impact report Mitigation of environmental impacts was studied and summarized in a report issued in June 2006. The recommended remedies, which were certified without challenge, included the establishment of quiet zones to restrict routine train horn use at grade crossings, and the replacement of specific wetland ditches.
On October 10, 2013, SMART announced that it had obtained more than of an area in Novato known as the "Mira Monte Marina." The purchase was executed to restore the area and preserve tidal wetlands, specifically mitigating of project impacts determined through the environmental review process and providing a land bank for future construction phases.
Funding The project is funded by federal, state, regional, and local allocations, including bridge tolls, dedicated sales tax revenues, and fares. The capital cost of track rehabilitation for the full line, signals, and railcars was originally estimated to be about $450 million in 2008 ($ adjusted for inflation). By 2019, development of the line from Airport Boulevard in Santa Rosa to the San Rafael Transit Center had consumed $448 million, and the estimated cost to complete the legislated system had increased to $944 million.
In November 2006, Measure R, a proposal for funding through an increase in sales taxes, received a combined 65.3% "yes" vote in the two-county District (70.1% in Sonoma County and 57.5% in Marin County). The measure failed because it lacked the two-thirds supermajority required for passage.
Measure Q, a similar proposal, was approved on November 4, 2008, receiving a combined vote of 69.5% (73.5% in Sonoma County and 62.6% in Marin County). It provided project funding through a quarter-cent sales tax in both counties set to expire in 2029. The Great Recession severely reduced the tax base, forcing the agency to build the project in phases; the tax was projected to generate $890 million over its lifetime, but the first decade yielded only $289 million. By fiscal year 2024, Measure Q generated $48.8 million in annual sales tax revenue.
In March 2020, SMART proposed Measure I to extend the quarter-cent sales tax for thirty years past its 2029 expiration. The measure received 51.2% of combined votes district-wide (49.8% in Sonoma County, 53.5% in Marin County), falling short of the two-thirds supermajority threshold by approximately fifteen percentage points; the campaign cost exceeded $3 million, the most expensive North Bay ballot measure to that date.
A citizen-led initiative campaign collected approximately 57,418 validated signatures across both counties to qualify a 30-year sales tax extension for the June 2, 2026, primary election ballot. Under a 2024 change to California law, the measure requires only a simple majority for passage because it qualified through voter initiative rather than board referral. Ahead of the vote, opponents including developer John Gallaher funded a book characterizing SMART as a "taxpayer ripoff" and "failed experiment". On June 2, 2026, the sales tax extension, titled Measure B, passed with 74.59% of the vote.
The SMART board authorized the sale of bonds in late 2011; proceeds were placed into an escrow account until an effort by a local taxpayer group to repeal the sales tax was legally resolved. In May 2012, SMART issued nearly $200 million in bonds to fund the immediate construction of the IOS, with debt service backed by the Measure Q quarter-cent sales tax revenue.
Initial operating segment track rehabilitation In January 2012, SMART completed negotiations to rebuild the Initial Operating Segment (IOS) between Airport Blvd in Santa Rosa and the Civic Center Station in San Rafael under the original budget estimate. The segment was completed jointly by Stacy and Witbeck and Herzog Contracting Corp. In 2012, SMART added two stations to the IOS design: north Santa Rosa, near Coddingtown, and Novato at Atherton Avenue.
The Puerto Suello Hill Tunnel in San Rafael was structurally rehabilitated for passenger service, and the 111-year-old fixed span Haystack Bridge over the Petaluma River was replaced with a movable bascule bridge. Concrete ties were installed along the line to support track speeds up to , and several legacy freight spur lines were removed to adhere to federal safety standards. Businesses can reconnect a switch and spur to the line for approximately $300,000.
The first phase of construction did not include the continuous parallel pedestrian and bicycle path originally envisioned, prioritizing rail infrastructure over the trail network to stay within budget.
Delayed start of service Scheduled passenger service was originally planned for 2014, but was delayed to late 2016 due to funding shortages tied to the economic downturn.
In late 2016, the agency delayed opening the IOS to "late spring 2017." The primary cause was a design flaw discovered in July 2016 when a near-identical Nippon Sharyo train operating on Toronto's Union Pearson Express experienced an engine fire. The issue was traced to a flaw in the Cummins QSK19-R engine's crankshaft that caused premature wear. SMART preemptively recalled all of its vehicles to its Rail Operations Center to rebuild the engines and replace the crankshafts prior to entering revenue service. Concurrently, the agency experienced problems with warning systems at some grade crossings and had not completed its positive train control approval process with the Federal Railroad Administration. The 2017 California floods also caused landslide damage near the Puerto Suello Hill Tunnel, further delaying physical testing of the line.
Preview service and excursion trips timed with the Marin County Fair began on June 29, 2017, offering free fares as far south as Marin Civic Center. Full revenue service commenced on August 25, 2017.
Larkspur segment
San Rafael bore costs estimated at $6 million (2012) for the Andersen Drive crossing of the Larkspur to San Rafael segment. The street was extended in the mid-1990s to cross the tracks on a temporary road. In July 1997, the California Public Utilities Commission required the city to fund the crossing's restoration prior to SMART operations.
In 2010, the agency received a federal earmark of $2.5 million for technical, environmental, and engineering design on the segment. Later that year, the rehabilitated California Park Tunnel ( wide, tall, and long) opened to pedestrian traffic. The $28 million renovation was funded equally by Marin County and SMART. The tunnel accommodates both the rail right-of-way and a bicycle/pedestrian path.
In May 2013, the SMART board approved the San Rafael to Larkspur link as its preferred alternative. On September 24, 2013, SMART was accepted into the Federal Transit Administration's "Small Starts" program. The FY2016 federal budget included construction funds for the Larkspur Extension. Construction contracts were awarded to a joint venture of Stacy and Witbeck and Herzog Contracting Corporation for $36.3 million. Work commenced in late 2017. In April 2018, SMART was awarded a $22.5 million federal grant for the extension. Final costs totaled an estimated $55.4 million. System testing began in August 2019 and concluded by late October. Revenue service commenced on December 14, 2019.
The Novato Downtown station, partially built during the IOS construction phase, officially opened alongside the Larkspur extension.
2019 service disruptions Service was cancelled on October 28 and 29, 2019, due to preemptive utility power shutoffs affecting the grade crossing signal infrastructure. Partial service to Downtown Santa Rosa was restored on October 30, and full service returned the following day with free rides offered through November 6, serving residents impacted by the Kincade Fire.
During weekends in November 2019, service gaps occurred between Petaluma and Novato–Hamilton to accommodate testing for the Downtown Novato station. A bus bridge operated with transfers at San Marin.
2020–22 operational changes During the COVID-19 pandemic, SMART reduced its schedule to 8 weekday round trips with no weekend service. In May 2021, service increased to 13 weekday and 6 Saturday round trips. Backed by $3.2 million in federal stimulus funds, the agency restored pre-pandemic schedules in 2022.
In May 2020, SMART acquired control of freight operations from the Northwestern Pacific Railroad. The state funded the $4 million purchase of rolling stock, track rights, and related properties. The agency took full ownership of freight operations and of trackage north of Healdsburg in July 2021. Sunday service resumed on May 1, 2022.
North of Santa Rosa
In 2018, the extension to Windsor was expected to cost $55 million, sourced from Road Repair and Accountability Act funds, Regional Measure 3 funds, and a federal grant. By November 2019, the estimate rose to $65 million.
The segment from Santa Rosa to Cloverdale was initially intended for the first phase but was delayed due to funding constraints. By May 2019, the estimated cost to reach Cloverdale and Healdsburg was $364 million. A 2020 study estimated the cost of reconstructing the Russian River bridge and the Healdsburg station at $32 million.
Work on the Windsor extension was temporarily suspended in 2021 pending the outcome of a regional toll lawsuit. A lawsuit dismissal in January 2023 freed $40 million for the agency, followed by a $34 million state grant. On July 5, 2023, the California Transportation Commission awarded SMART a $30 million grant to fund the Windsor and Healdsburg extensions. The extension includes trackage running north of Healdsburg station to the city limits.
Windsor station opened on May 31, 2025. As part of a 2025–26 Metropolitan Transportation Commission regional coordination effort, local transit providers including Marin Transit, Petaluma Transit, Santa Rosa CityBus, and Sonoma County Transit restructured bus service to connect with SMART stations rather than parallel the rail corridor. Service changes on April 12, 2026, increased SMART service to 24 weekday round trips and 12 weekend round trips; bus schedules also changed at that time.