Unlocking Sustainable Shared Mobility: A Hybrid Choice Model of Docked Bike-Sharing Adoption with Latent Accessibility Perceptions

Cities are often defined by their movement, or the lack of it. When traffic jams, pollution, and the slow creep of congestion become daily realities, planners look for ways to untangle the knot. One promising solution is the bike-sharing system, a network of bicycles available for public use that aims to replace short car trips with human-powered travel. For these systems to work, they cannot simply be dropped into a city at random; they must fit into the rhythm of daily life. This means stations need to be near where people work, study, shop, and catch buses. But beyond the physical location of a bike rack, there is a more subtle factor at play: how people feel about how easy it is to reach these places. Do they believe a bike station is close enough to their office or the university? Do they feel safe riding there? Understanding the gap between the physical map and the human mind is crucial for making shared mobility a reality, especially in growing cities where infrastructure is still catching up.

In the city of Gorgan, Iran, a team of researchers set out to understand exactly what drives people to choose a shared bike over a car, a taxi, or a bus. They focused on a specific group: people who travel for work or school, the kind of daily trips that are non-negotiable and often the most congested. To get to the heart of the matter, they did not just ask people what they did; they asked them what they would do under different conditions. They interviewed 378 commuters and students, presenting them with a series of hypothetical scenarios. In these scenarios, the cost of renting a bike changed, the type of bike lane available shifted from a protected path in the middle of the road to a shared lane with cars, and the features of the bike itself varied. The researchers also asked these participants to rate their agreement with statements about where bike stations should be placed relative to universities, offices, shopping malls, restaurants, and public transit stops. By combining these answers with a statistical model that accounts for hidden attitudes, the team could see not just what factors mattered, but how people's perceptions of accessibility shaped their willingness to ride.

The study revealed that the physical environment is the most powerful driver of choice. The type of bike lane made a massive difference. When a dedicated, protected lane separated cyclists from motor vehicles, the willingness to use the system soared. Specifically, lanes protected by a median strip in the center of the road were the most effective, followed by lanes protected by curbs. In stark contrast, the fear of sharing the road with cars in mixed traffic significantly discouraged people from using the system. Price also played a clear role; as the cost of renting a bike went up, the likelihood of choosing it went down. However, the researchers found that the physical safety of the route mattered more than the price. Even with a free bike, people were less likely to choose it if they had to ride in mixed traffic, but they were much more willing to ride if a safe, separated lane was available.

Beyond the road and the price tag, the researchers discovered that a person's perception of where the bikes are located is just as important as the location itself. They found that people who felt the stations were close to their daily destinations were far more likely to use the system. This feeling of accessibility was strongest when stations were near public transit stops, such as bus stations, followed closely by universities and offices. Interestingly, while proximity to restaurants and shopping malls also helped, it had a slightly smaller effect. The study showed that these perceptions are not random; they are shaped by who the rider is. University students, people without a car at home, and those with higher education levels tended to have more positive views of bike accessibility. Conversely, people with higher body mass indices or those who had complex daily schedules with multiple stops felt less confident about the system's accessibility, likely because the fixed nature of returning a bike to a specific station felt less flexible than a private car.

To turn these insights into action, the researchers created a new tool called a Station Suitability Index. This is essentially a scoring system that helps city planners decide exactly where to put the next bike station. By weighing the amount of space dedicated to universities, offices, malls, and bus stops in different parts of the city, the index identifies the zones where a new station would be most useful. When they applied this index to Gorgan, they found that the western and central parts of the city were the best candidates for expansion, while the eastern edges were less suitable due to a lack of these key destinations. The study also calculated the environmental payoff of this strategy. They estimated that if the system were adopted as predicted, it would remove about 91.6 tons of vehicle emissions from the air every year. When valued in terms of the health and environmental damage these pollutants cause, this reduction is worth more than $76,000 annually. This suggests that for a mid-sized city in a developing country, investing in a well-planned bike-sharing network is not just an environmental gesture, but a financially sound decision that can pay for itself through the savings it generates.

The findings from Gorgan offer a clear roadmap for other cities facing similar challenges. It is not enough to simply build bike lanes or place stations near a bus stop; the system must be designed with the rider's sense of safety and convenience in mind. Protected lanes are non-negotiable for building trust, and stations must be clustered around the places where people actually spend their days. By understanding the invisible link between a person's attitude and their travel choices, cities can move beyond guesswork and build shared mobility systems that people actually want to use. The research suggests that when the infrastructure is safe and the stations are where people need them, the shift from car to bike becomes a natural, logical choice for the daily commute.