Reserved for vehicles with a minimum number of occupants, generally two or three people, they encourage the circulation of shared vehicles to reduce traffic and pollution.
In contemporary cities, mobility is one of the main pressures on urban space and the environment. The constant increase in private traffic, combined with lengthening travel times, requires a rethinking of travel policies. The challenge lies not so much in building new infrastructure, but in using existing ones more efficiently, promoting sharing strategies and forms of cooperation that reduce the overall burden on the system.
As with bike lanes, which foster a new culture of public space based on the coexistence of diverse users, the same principle can be applied to car mobility: not to expand space, but to improve its quality of use. This involves encouraging civic behavior and sharing practices that increase the system’s efficiency without new infrastructure costs, addressing not only the physical dimension, but above all the organizational and behavioral dimensions.
HOV ( High-Occupancy Vehicle ) lanes are one of the most representative applications of the principle of saturation economy. Reserved for vehicles with a minimum number of occupants, generally two or three people, they run parallel to main arteries and encourage the circulation of shared vehicles, with a dual objective: reducing congestion and pollution, and encouraging collaborative behaviors aimed at a more rational use of space.
The image exemplifies how the HOV system works: the diamond symbol and the wording ” HOV 2+ / 2 or more persons per vehicle ” communicate a clear and legible rule, based on car sharing as a civic and environmental choice. From this perspective, the signage also takes on a cultural value, expressing the logic of the saturation economy, in which efficiency comes not from new infrastructure but from a different way of using public space.
HOV lanes emerged in the United States in the early 1970s, a period marked by urban sprawl and the energy crisis. Their introduction was supported by federal policies for energy conservation and pollution reduction, enacted by the Clean Air Act of 1970 and the Energy Policy and Conservation Act of 1975.
The following road sign, indicating the minimum number of occupants, clearly communicates that priority goes to those traveling together. It doesn’t impose rigid restrictions, but rather guides choices by gently nudging them toward more cooperative behavior. Thus, signage becomes a tool for shared mobility and a more efficient use of road space.
Over the past few decades, HOV lanes have spread across Canada, Australia, the United Kingdom, and several European cities, becoming a stable tool in mobility demand management policies aimed at reducing congestion and emissions. Recent analyses by the OECD ( Shared Mobility and Urban Efficiency: Towards Inclusive and Sustainable Transport Systems , 2022) and the ITDP ( High Occupancy Vehicle Lanes: Lessons from Jakarta and Beyond , 2021) confirm that they are a good urban planning practice, capable of increasing the overall efficiency of transportation systems and contributing to environmental sustainability.
Although this model is not yet envisaged in the Italian regulatory framework, international evidence shows significant impacts: a 10% to 20% reduction in private traffic during rush hour, a 15% to 30% increase in average traffic speed, and a general improvement in traffic flow (Schijns, 2006). These results demonstrate the potential of HOV lanes as an effective lever in sustainable mobility policies.
Like bike lanes, which don’t force people to change vehicles but make green mobility more accessible and safer, HOV lanes function as a nudging policy typical of next-generation policies. They don’t impose mandatory behaviors or drastic limitations, but guide individual choices toward more efficient and collective modes, making cooperation between users the simplest, fastest, and most convenient option. This “gentle nudge” incentivizes socially beneficial behaviors by enhancing existing infrastructure and improving the overall efficiency of the system without incurring new costs.
Even experiences outside of the European context offer useful insights. In Jakarta, the “3-in-1” system has shown how a rule can rapidly change the conditions of urban mobility, generating immediate adaptations from users. As documented by The Guardian (2016) : “A woman carries her baby as she signals to show that she’s for hire as a ‘jockey’ to help drivers cheat a peak time traffic rule…” https://www.theguardian.com/world/2016/apr/04/end-of-the-road-jakartas-passengers-for-hire-targeted-by-carpooling-crackdown .
To understand how the philosophy of saturation, understood as an applied territorial efficiency approach, can translate into operational models such as HOV lanes and cycle lanes, we explore the topic further with Alessandra Proto, Director of the OECD Trento Centre for Local Development.
Established in 2003 with the Italian Government and the Autonomous Province of Trento, the Center, part of the OECD Center for Entrepreneurship, serves as an international platform for strengthening territorial development policies. Focused on territorial productivity, multilevel governance, administrative capacity, and public policy effectiveness, it promotes evidence-based approaches and institutional innovation. Through applied research, comparative analyses, and capacity-building programs, it supports local authorities in transforming OECD evidence into integrated and sustainable strategies, leveraging existing resources.
Director Proto, how can the examples of HOV lanes and cycle lanes, understood as sustainable mobility infrastructure, relate to the OECD vision of spatial productivity and place-based policies?
HOV lanes and bike lanes are infrastructure perfectly consistent with the OECD approach to place-based policies, as they enhance existing urban networks and spaces through a more efficient and coordinated use of land resources. These interventions improve connectivity, reduce congestion, and promote more equitable access to services, with direct impacts on local productivity.
Territorial productivity, from the OECD perspective, is closely linked to accessibility, travel times, and the reliability of mobility. Well-connected territories allow businesses and workers to reach markets and opportunities more quickly, reducing the so-called commuting productivity penalty , or the loss of output due to long or inefficient travel. Improving mobility therefore means increasing effective productive time and the quality of work, generating both economic and social benefits.
Experiences such as HOV lanes and bike lanes also allow for testing place-based approaches adapted to local contexts: they are true regional laboratories where innovation, sustainability, and inclusion intertwine. Efficient transportation systems, like a streamlined public administration or an efficient justice system, are key factors in urban productivity. Reducing congestion, promoting active mobility, and integrating transportation policies with local development policies thus contribute to strengthening competitiveness, tourism, and the overall attractiveness of regions.
To what extent can the philosophy of saturation, applied to integrated mobility and museum access policies that allow more people to benefit from the same services at a reduced cost, be considered a form of territorial efficiency according to the OECD vision?
Although the OECD does not yet have specific studies on the saturation philosophy applied to public services, this approach can be interpreted as a form of territorial efficiency. Integrating mobility and access to cultural services, for example through coordinated pricing policies and unified ticketing systems like those adopted in Trentino, increases use without generating new costs or infrastructure investments. This model leverages existing resources—transport networks, cultural spaces, and existing facilities—expanding accessibility and reducing environmental impact.
From the OECD perspective, these types of interventions reflect the principles of spatial productivity and institutional cooperation, as they optimize infrastructure and services through connections between public and private actors. Efficiency does not derive from expanding supply, but from the ability to network functions and resources, generating collective value and inclusion.
There is also a direct link to local well-being: improving equitable access to cultural and mobility services means offering opportunities to those typically excluded, reducing inequalities and increasing quality of life. The OECD highlights how inequalities and inefficiencies are often two sides of the same coin: a more equitable region is also more productive and resilient. From this perspective, inclusion, equity, and collective efficiency become essential components of any sustainable local development strategy.
What are the center’s main current lines of work in analyzing spatial productivity in local areas?
The concept of spatial productivity is at the heart of a renewed paradigm of territorial development. The OECD views space not as a neutral container, but as a productive resource: its configuration influences the ability of regions to generate value, innovation, and well-being. The most dynamic local economies are those that transform proximity, density, and connectivity into competitive advantages, making space a factor of efficiency and cohesion.
Territorial productivity depends not only on physical or technological capital, but also on the structure of space and the quality of interactions that occur within it. Efficiency arises from the balance between concentration and accessibility, between functional density and environmental quality, in a perspective that integrates economics, planning, and social cohesion. To support this vision, the OECD promotes multidimensional measurement tools that analyze land use, mobility connectivity, service provision, and local innovation capacity, providing internationally comparable indicators to guide urban and regional policies based on spatial efficiency and sustainability.
The most current lines of research focus on the labor market and the factors that determine its productivity. These include skills mismatch, inefficient workforce allocation, and the quality of educational and vocational training. Demographic, technological, and environmental transformations, including those related to artificial intelligence, are redefining the demand for skills and the ability of regions to attract talent. In this scenario, geographic and professional mobility plays a crucial role: encouraging people to move towards more relevant and rewarding jobs means strengthening inclusive productivity and improving the overall efficiency of regional systems.
What governance conditions enable a leap in scale toward more productive and collaborative management of space?
Effective governance of spatial productivity requires integration, continuity, and a long-term vision. Sectoral policies—mobility, housing, environment, welfare—must interact with each other and converge into coherent territorial strategies, overcoming administrative and institutional fragmentation. This requires institutions capable of coordinating resources and expertise at multiple levels, generating synergies between the public, private, and community sectors.
The role of cities and intermediate areas is crucial: they are laboratories where integrated mobility, service, and urban regeneration solutions are tested. Here, governance is not just a technical process, but a relational practice based on trust and cooperation. The productivity of space also depends on social capital, understood as the intangible infrastructure of collaboration and shared learning.
OECD analyses show that the most productive systems adopt adaptive governance models, based on empirical evidence, continuous evaluation, and the capacity for collective learning. Within this framework, Trentino represents a unique context: thanks to its institutional autonomy and a short decision-making chain, it has sophisticated coordination mechanisms and advanced legislative tools. However, its true competitive advantage lies in its highly integrated stakeholder ecosystem, capable of bringing together institutions, research, businesses, and local communities—a rare condition that enables truly collaborative governance geared toward territorial productivity.
How are productivity and the sharing economy intertwined, for example through practices like carpooling, car-sharing, coworking, cohousing, or the collaborative use of public spaces?
In recent years, the OECD has paid increasing attention to phenomena related to the social economy and cooperatives, areas where analyses and data are more consolidated. In this context, Trentino represents an advanced laboratory: thanks to a short institutional supply chain and a highly integrated ecosystem of public, private, and community actors, it has succeeded in translating the philosophy of sharing into a structural approach to local development. Of particular importance are “third places,” work and social spaces that foster collaboration, social innovation, and regional well-being, improving the quality of professional conditions and the ability to generate collective value.
From this perspective, the sharing economy appears as a natural extension of the concept of spatial productivity. Both are based on the idea that value emerges from interaction, not ownership. Practices such as carpooling, coworking, cohousing, or the collaborative use of public spaces demonstrate how existing resources can be used more intensively and in a more coordinated manner, reducing costs, emissions, and waste, and improving the quality and efficiency of territorial systems.
From an economic and social perspective, these models generate allocative efficiency and transform individual assets into collective infrastructure. Every shared vehicle, regenerated space, or cooperative home has a multiplier effect on local capital, strengthening accessibility, cohesion, and quality of life. It is a form of widespread productivity, founded on trust, reciprocity, and civic responsibility, which translates collaboration into economic, social, and environmental value. In this regard, the sharing economy stands as one of the pillars of the transition to a sustainable and inclusive development model, in line with the OECD perspectives on collaborative territorial growth.
Luciano Malfer, technical director of the European Network of Family-Friendly Municipalities