New Insights from French Researchers on Long-Distance Carpooling Dynamics

Researchers from France's Laboratoire Aménagement Économie Transports (LAET) at École Nationale des Travaux Publics de l'État (ENTPE) and Université de Lyon have published a pivotal exploratory study examining the supply of long-distance carpooling services and the role of public financial incentives. Titled "Exploratory study of long-distance carpooling supply and public financial incentives: The case of France," the paper appears in Transportation Research Part A: Policy and Practice in March 2026. Long-distance carpooling, defined as trips exceeding 80 kilometers, has gained traction as a sustainable alternative to solo driving and rail travel, especially amid France's push for greener mobility under the national Sustainable Mobility Package.

The study, led by Florent Laroche and Kseniya Schemeleva, analyzes proprietary data from 2020 to 2024, capturing the evolution of carpooling platforms like Klaxit (now integrated into BlaBlaCar Daily). It comes at a critical time as France aims to triple daily carpooling trips to three million by 2027, potentially avoiding three million tons of CO2 emissions annually. This research highlights the interplay between policy interventions and market realities, offering valuable lessons for academics and policymakers across Europe.

French Policies Driving Sustainable Transport Incentives

France has positioned carpooling as a cornerstone of its ecological transition. The Plan National Covoiturage du Quotidien, launched in December 2022, allocates €150 million annually through 2027 to boost usage. Key measures include the Forfait Mobilités Durables, allowing employers to reimburse up to €900 per employee tax-free for sustainable commuting, including carpooling. Local authorities match incentives via the Fonds Vert, subsidizing passenger fares or driver primes.

For long-distance trips, platforms facilitate cost-sharing limited to actual expenses (fuel, tolls, at €0.20/km per passenger max). Reserved lanes on highways, tested since 2019 under the Loi d’Orientation des Mobilités (LOM), prioritize carpoolers. However, challenges persist: carpooling represents just 3% of daily motorized trips, with platforms covering only 4% of organized rides. The government's ambition addresses the 70% solo car commuting rate, amid rising fuel costs and rail disruptions.

The €100 New Driver Subsidy: Design and Implementation

In 2023, France rolled out a €100 incentive for first-time long-distance carpooling drivers on certified platforms: €25 after the initial trip, €75 after ten more within three months. Aimed at expanding supply amid post-COVID recovery, it targeted drivers to foster network effects. Extended briefly beyond 2023 for ongoing claimants, it was phased out for new users by 2025 amid evaluations.

Platforms like BlaBlaCar and Klaxit promoted it heavily, integrating with apps for seamless claims. Yet, fiscal rules cap reimbursements to prevent professionalization, ensuring carpooling remains occasional sharing. This scheme exemplifies targeted nudges in behavioral economics, but its efficacy required rigorous scrutiny—the focus of the LAET study.

Methodology: Rigorous Empirical Analysis of Platform Data

Laroche and Schemeleva's approach combines descriptive and econometric tools. Seasonal-Trend decomposition via LOESS (STL) disentangles cyclical patterns from COVID impacts. A multiple linear regression (MLR) model then regresses new driver registrations on subsidy dummy, intermodal variables (e.g., train availability), intramodal factors (trip distances, pricing), and controls like seasonality and regional density.

Data spans 2020-2024 across France's carpooling hotspots, sourced confidentially from Klaxit. This granularity allows causal inference on policy shocks. The model specification accounts for multicollinearity, with robust standard errors. Such methods, common in transport economics, bridge platform microdata with macro policy evaluation.

COVID-19's Lasting Shadow on Carpooling Growth

STL analysis reveals stark trends: 2020 lockdowns slashed supply by over 80%, rebounding sharply in 2021-2022 as remote work waned and rail resumed. 2023 showed continuity, not acceleration from subsidy. Pre-pandemic baselines (2019 proxies) underscore pent-up demand, with platforms like BlaBlaCar reporting 272,000 tons CO2 saved in 2018 alone at average 239km trips with 3.5 occupants.

Photo by Ludovic Charlet on Unsplash

• 2020: Sharp decline due to mobility bans.
• 2021-2022: Recovery to 120-150% pre-COVID levels.
• 2023-2024: Stabilization, seasonal peaks in summer/vacations.

Core Finding: Subsidies Fall Short on Driver Supply

The MLR confirms the €100 incentive's coefficient is statistically insignificant (p>0.05), suggesting limited causal impact on new drivers. Marginal effects show other variables dominate: train disruptions boost odds by 15-20%, peak seasons by 25%. This challenges subsidy optimism, aligning with behavioral studies where intrinsic factors (convenience, altruism) outweigh cash.

Quantitatively, subsidy rollout coincided with no disproportionate supply surge versus counterfactuals. Elasticity estimates imply €1 extra subsidy yields negligible drivers, versus targeted marketing's 2-3x effect.

Train Shortages and Peaks: True Supply Catalysts

New drivers cluster where SNCF high-speed services falter—strikes, delays, engineering works. Coefficient on train shortage index: +0.18 (p<0.01). Seasonality shines: July-August surges 30% from vacances, filling modal gaps.

Intramodal: Longer trips (>300km) attract prosocial drivers; pricing below €0.10/km/passenger km signals sharing intent. Regional: Rhône-Alpes, Occitanie lead, urban-rural links thrive.

Carpooling as Rail Complement, Not Competitor

Intermodal synergy: New supply rises 22% during TGV capacity crunches, positioning carpooling as flexible backup. Paris-Lyon, Marseille-Toulouse axes exemplify, with platforms matching 70% unmet rail demand in peaks. This bodes well for multi-modal ecosystems, per EU Sustainable & Smart Mobility Strategy.

Stakeholders: Platforms gain users; rail operators offload pressure; environment wins via 2-4x occupancy vs solo cars.

Policy Lessons: Beyond Cash to Systemic Support

Findings urge nuance: Subsidies suit demand-side (passengers), supply needs infrastructure (lanes, apps, trust verification). Cost-benefit: €100/driver yields <1 new trip/month. Redirect to matching algorithms, employer mandates? Balanced views from ADEME surveys note rebound effects, yet net GHG cuts.Read the full LAET study

Challenges: Free-riding, safety perceptions. Solutions: Verified profiles, insurance pools.

European Parallels and Opportunities

France leads EU carpooling (12M platform trips 2024), but peers lag: Germany's Mitfahrgelegenheit grows 15% YoY; Netherlands incentivizes via tax breaks. EU Mobility Strategy eyes shared modes for 90% emission cuts by 2050. Studies echo: Incentives amplify in scarcity. For Europe-wide, harmonize apps, cross-border lanes.Discover higher-ed opportunities in Europe

Photo by Renaud Confavreux on Unsplash

Future Directions: Research and Innovation

LAET calls for longitudinal subsidy trials, behavioral nudges, EV integration. Platforms eye AI matching; unis like ENTPE pioneer data-sharing. Outlook: With ridesharing CAGR 10-16% to 2030, academic-transport collab key. Explore research jobs advancing sustainable transport.

Conclusion: Paving Greener Roads Ahead

This ENTPE study underscores evidence-based policy for sustainable transport incentives. While financial primes alone underwhelm, leveraging shortages and seasons unlocks potential. For Europe's net-zero goals, multi-stakeholder strategies—academia, gov, platforms—promise scalable impact. Researchers eyeing transport careers, check higher-ed-jobs, university-jobs, rate-my-professor, and higher-ed-career-advice for insights and openings. Share your views below.