In the mid-1900s, Dutch citizens of Delft were sick of cars driving too fast down their narrow residential streets. The city was slow to respond, so residents took matters into their own hands. Groups of neighbors came together and tore up sections of pavement, then put up planters and other partial obstructions, often overnight to avoid traffic or official resistance. Their traffic-calming urban interventions were simply designed to slow down cars and reclaim streets. The government initially turned a blind eye to this illegal activism and eventually came to embrace new “woonerf” (or: living street) configurations. The Dutch Parliament  even enshrined woonerven strategies in national law as part of shift toward making the nation less car-centric.

The Netherlands in particular is well-known for being friendly to cyclists and pedestrians, but around the world there is a growing resistance to the dominance of motorized vehicle culture. Car critics note that personal cars not only add to pollution and street dangers but they also take up a lot of road and parking space, which, among other things, makes real estate more expensive for everyone. In a world largely designed around cars, pedestrians can at least can hope for sidewalks in some places but bikes often have to share the road, for better or worse.

A lot of workarounds for cyclists have been developed over the years, like “sharrows” to remind drivers to be aware of two-wheeled vehicles sharing the streets. There are tricks like the “Dutch Reach,” a car door-opening approach parked drivers are encouraged to use to avoid hitting cyclists; basically, it involves using the hand furthest from the door, resulting in an overreach that forces the driver to look backward briefly. For their part, some cyclists strap things like pool noodles to the backs of their bikes, a visible reminder of how much clearance they are entitled to while riding in lanes or along shoulders. Activists have taken things further, too, installing guerrilla bike lanes with whatever is at hand, from official-looking posts and traffic cones to toilet plungers. The idea here is to spur cities into action, using temporary measures to encourage permanent changes.

In many places, car-curbing efforts have begun to gain traction on a larger scale, driven in part by this kind of citizen activism. Cities like Paris have proclaimed car-free days so people can walk, bike and play in the streets. There are also some longer-term official plans to oust private vehicles from major metropolitan areas and there have even been proposals to create entirely new car-free cities from scratch.

A number of ambitious projects aim not just grow walking and cycling routes but also to better connect these across cities — prominent examples include a 60-mile “bike autobahn” across Germany, an adaptation of America’s famously Route 66 for cyclists and an extensive elevated bicycle path in China. One particularly bold proposal would create a raised cycling route running over 100 miles around London. Holland, as usually, as ahead of the curve, home to the world’s largest bike parking garage as well as the first raised roundabout for cyclists.

While some of these plans call for vast overhauls and dramatically reworking existing infrastructure, conversion approaches like those advocated by the rails-to-trails movement take advantage of lower-hanging fruit, transforming unused train lines and other abandoned routes into functioning pathways. New Yorks’ High Line helped spark the elevated greenway trend in particular, but the idea has since spread to cities like Los Angeles, Chicago, Singapore and more. In some cases, where elevated routes are still in use by cars or trains, new trails have been introduced underneath trains and highways instead.

Some futurists think self-driving cars will solve a lot of traffic problems and collision concerns for pedestrians, cyclists and car drivers alike. Optimistic estimates suggest autonomous vehicles will reduce emissions dramatically while freeing up space currently used for parking, all while making streets safer from distracted human drivers. Other experts, though, warn that as cars become more comfortable places to lounge, more people will end up using them more often and over longer distances, further clogging up city streets and highways.

For now, full automation is still more science fiction than urban fact. In the meantime, there is evidence to suggest that simplicity may be the best way forward — that getting rid of signals, signs and barriers might actually make streets a lot safer. While some cities have attempted to confuse drivers into slowing down, other towns all over Europe are starting to experiment with streets on which cars, buses, bikes and pedestrians can all travel more freely. This type of “shared space” approach eliminates distractions while also encouraging drivers to focus on their surroundings more closely. Sometimes, less really is more.

A long unused strip of space weaving through Berlin is set to become a bicycling boulevard, sheltered by the tracks above and lined with bike service stations, recreation areas and food trucks. This latest rails-to-trails project has six miles of space to work with, connecting major roads and multiple neighborhoods. Completely disused aside except as illegal parking and intermittent strips of sidewalks and seating, the area below the U1 line is ripe for rehabilitation.

As in other cities with similar programs, the Radbahn aims to serve not only as a traffic corridor and green trail but also to activate adjacent spaces. Pocket parks and commercial vendors are expected to spring up along the route, and side extensions can bring bikers down to adjacent waterways and other natural features.

Meanwhile, riders can enjoy a rain-free experience (it rains over 100 days per year in Berlin). Cyclists looking to take the train can also park their ride in sheltered spaces below the rails near stations. The minimum width and consistent coverage of the tracks above provide for a sufficiently wide trail from start to finish, while studies have shown that train noise below tracks is reduced as compared to adjacent space.

Per the proposal, the goal is “revitalize the former space along the iconic U1 line to a pulsating urban artery. It thereby acts as a playground for modern mobility, innovation and leisure activities.” In typical German fashion, the project designers and engineers have already extensively documented and mapped opportunities throughout the route, which you can explore in greater depth by visiting their website.

The new Freezeway pilot project now live in Edmonton aims to draw residents out of hibernation, encouraging them to skate along an iced trail system slated to double as a seven-mile commuting corridor.

What started as a landscape architecture student’s conceptual project has already become a 1,300-foot ice pathway in winter that also serves as a bike route during the summer.

The vision is well-adapted to the conditions of the city, which faces below-freezing temperatures for up to five months out of the year, and has been nicknamed Deadmonton for its lack of wintertime outdoor activity.

The opening of the first stretch of Freezeway has been accompanied by a disco-style light show of rainbow colors projected onto the frozen path.

From the designer: “This project is not meant to be a tax payer’s burden. The Freezeway is meant upgrade city infrastructure for a multitude of uses, potentially doing wonders for the redeveloping City’s core, our international reputation, as well as attract investment into the City. The proposed route exists entirely on existing City infrastructure; the land is already secured. The numerous character areas along the route could be developed in phases, lending themselves well to private funding/sponsorship, like Calgary’s GlobalFest, or Vancouver’s Festival of Light fireworks shows, funded by donations of over 1 million dollars annually.”

Boasting 5 miles of trails, ramps and obstacles, this cavernous subterranean space sits 100 feet underground and totals 320,000 square feet. The wide-open footprint and copious mounds of dirt, able to be endlessly reformed into new types of terrain, lend themselves to this particularly fitting form of adaptive reuse.

Located in Louisville, Kentucky, and open as of yesterday, the Mega Underground Bike Park gains a number of advantages from being far below the surface, including a relatively consistent temperature and protection from wind, rain and other weather (without the typical costs of constructing a building to house these activities).

Originally a limestone mine, there were plans to create a highs-security business park in the space – while there are a few businesses actually occupying other parts of the underground complex of caves, the big idea fell through, replaced by a plan to create zip lines, challenge courses and now the biggest interior bike park on the planet.

Currently the space offers 45 trails with differing degrees of of difficulty as well as clever additions like cargo containers turned into ramps and overpasses. Most of the materials needed, though, were already in place – it was mainly a matter of lighting, accessing and shaping the space.

From their website: “Are you ready to experience a one of a kind Underground Bike Park? Over 320,000 square feet including over 45 trails, Jump Lines, Pump Tracks, Dual Slalom, BMX, Cross Country and Single Track all in a former limestone cavern 100 feet sub-surface. Enjoy the comfort of our 60 degree temperature year round. Come experience what the buzz is all about. You simply won’t believe what you see.”