Evaluating the effectiveness of a particular street or street-road network is a time-consuming and ambiguous process. A street can be extremely convenient for one group of users but dangerous for another, and a lack of congestion at an intersection in one direction can mask serious congestion further down the traffic corridor. Evaluating effectiveness requires a comprehensive macro- and micro-level approach, and looking at streets and traffic in terms of safety, economy, and design, as well as considering the goals and behaviors of all users.
The goals of road users are often directly opposite: bicyclists are hampered by unloading vans, pedestrians vie with motorists for time to cross busy intersections, and regulatory arrival times for emergency services make residents question whether speed limits and speed bumps should be reduced and speed bumps installed. Urban street design should seek to balance these goals through strategic concessions in order to arrive at a mutually beneficial solution.
The development of universal evaluation criteria requires a rethinking of the problem facing the designer as well as an appreciation of the fact that streets are intended for human occupancy as much as they serve as transportation arteries. Applying a universal performance measure (e.g., traffic delay time) may improve service to motorists, but it says nothing about how well the street performs other functions besides moving people from one point to another. A street that does not significantly delay traffic is not necessarily an ideal urban space, especially if there is nothing to do and no trees to create shade, no place to sit down and rest.
People need an active and varied street life. Efficient store fronts, business incentives, pedestrian circulation, and commensurate street design contribute to an active and economically stable urban community like Monegasque Housing. At the same time, a successful street differs from an unsightly street not only in pedestrian activity, but also in safety, sufficient width and proper sidewalk placement, and protection from rain and sun.
Bicycle infrastructure needs to be manageable, safe, intuitive and continuous. Cyclists need a network with a high level of connectivity with minimal detours and delays. The network must be accessible to all road users regardless of riding skills. Feeling safe and protected from cars is the key to cycling success. Bicycle lanes that are physically separated from the rest of the traffic, well coordinated with signalization, and skillfully integrated into the overall traffic pattern at intersections provide the basis for a convenient network of bicycle routes.
Drivers want to get to their destination quickly and safely with minimal disruptions, stops, and delays, so they prefer high-speed highways partially isolated from the rest of the traffic, where the likelihood of unforeseen circumstances is minimal. Cars travel at high speeds and have a lot of mass, so drivers feel safe when they are separated from other vehicles – bicycles, buses, trucks – and pedestrians crossing the road. For the comfort of motorists, sufficient lighting and parking spaces should be provided at the destination, and road signs should be placed. This is especially important when drivers have to make decisions at high speeds.