If your city isn’t meeting your needs, just hack it. Urban hacktivism is a form of creative, citizen-led problem solving that often goes behind the backs of officials and institutions to get things done. Instead of leaving the task of shaping a given city to governments and developers, who tend to ignore the input of people they’re supposed to be serving, urban hacktivists take matters into their own hands by combining crowdsourced knowledge and skills with cheap, readily available materials. That might mean transforming a long-vacant lot into a neighborhood park, adding public seating to an area where it’s lacking, enhancing the safety of intersections for pedestrians or just making urban environments feel more responsive and fun.

At the heart of this kind of guerrilla urbanism is the ability to see the potential of public spaces to better meet people’s needs, make small changes and possibly convince local governments to make those changes permanent in the process. After all, the people who use those spaces every day know best. If you’re interested in carrying out some DIY urbanism in your own city, the internet is full of examples, guides and tutorials to get you started. These hacks may or may not be legal where you live – whether you choose to find a way around that is up to you, and most of these tools come with an obligatory disclaimer that they’re not suggesting, teaching or condoning any kind of illegal action.

Create DIY Crosswalks

Sometimes, cities just don’t seem to know where crosswalks belong. Maybe they’re not paying attention. Maybe there’s some kind of red tape involved. But a lack of proper crossings can be dangerous for pedestrians who simply aren’t going to take a stupidly long way around. If there’s a common crossing near you that isn’t marked, you can mark it yourself, whether by grabbing some paint and forming your own urban repair squad or setting up a temporary illuminated crosswalk, as laid out at Instructables. For guidance on paint selection and other aspects of this task, check out the Tactical Urbanist’s Guide To Getting it Done, a free resource you can download packed with tips for all sorts of projects.

Customize Street Signs

PHOTOS: These hacked electronic street signs make being stuck in traffic worth it http://t.co/XZkdOV8RdJ pic.twitter.com/pu9sFIx9eJ

— RYOT (@ThisIsRYOT) March 13, 2014

Some cities don’t have enough navigation signs to guide people to significant destinations. Some just aren’t adequately marked, like a misleading exit sign over the 110 freeway in Los Angeles, which one intrepid urban hacker fixed himself with a very convincing facsimile of official Caltrans signage (it stayed up for over eight years.) Street artists frequently “hack” signs just to make them more interesting and fun. And, just to say, electronic road signs are pretty easy to hack into just for the sake of making someone smile on their crappy commute, though of course you should never tamper with these signs, as instructions to do exactly that will warn you.

You can also produce your own street signs that look official at a glance, but actually spread positive messages in unexpected places. Seattle-based guerrilla artist April Soetarman sells her own rugged heavy-duty laminated aluminum signs that say things like “NOTICE: I never stopped loving you. I hope you’re well.” It’s easy to order your own custom street signs through any number of websites, all just a Google away, or you can do it through the Walk Your City Project, which links informational street signs “with web-based campaign management and data collection to complement traditional approaches to way finding.”

Hack Bus Shelter Advertisements

Brandalism, “a revolt against the corporate control of culture and space” by an international collective of artists, wants to help you intervene into ad spaces that usually celebrate consumption in favor of art, political messaging or whatever you’d rather look at instead. Carefully noting that the tools they offer “are handmade art objects and not intended for use,” the group maintains a site called PublicAdCampaign.com illustrating the types of tools required to get into bus shelter ads in various cities across the world. You can purchase these tools – er, art objects – directly from the website.

Build Your Own Bike Lanes

A lack of proper bike lanes is dangerous for everyone on the road, whether you’re a cyclist or a motorist. DIY bike lanes are almost always illegal, but that doesn’t stop people from making them anyway in a form of political vandalism that often forces officials to sit up and pay attention. The tactic can definitely pay off, as it’s not unusual for these temporary lanes – made of traffic cones, flower pots, or even toilet plungers – to eventually become permanent. Tactical Urbanism has a variety of tips in this area, along with case studies that show how it worked out in various cities.

Make Modular Structures Out of Found Objects

Hacking cities needn’t (and arguably shouldn’t) involve the purchase of expensive, heavy, potentially waste-producing materials. DIY urbanists are encouraged, instead, to “hack” into existing modular systems to make them work for new purposes. Examples include Mifactori’s “Circular Street Waste” workshop, in which discarded furniture and other trash collected from the city streets is transformed into versatile multi-use parts that could become tables, benches, shelters and more.

Similarly, the 3erlin Grid (say “Berlin Grid”) offers a grid-based decentralized open standard for building objects and structures that always leaves a distance of 3cm between holes for nuts and bolts so all parts always fit together and can be combined in infinite ways. So if one person builds, say, a DIY table for a city, someone else can come along and add to it. They’re often based on children’s toys, found objects that can be easily modified, like fencing and scaffolding. The principles follow those of OpenStructures, which include using recyclable materials, designing for disassembly and making components as cross-compatible as possible.

Many tactical urbanism projects are self-explanatory, and easy to recreate just by looking at what other people have accomplished. Check out some of our previous posts on urban hacking for a whole lot of inspiration.

Tactical Urbanism: 15 Low-Cost City Hacks for Fun & Functionality

The Rotten Apple Project: Quick & Dirty Urban Hacks

City Hacktivism: 12 Fun DIY Urban Interventions

Hack Your City: Guerrilla Grafter’s Guide for Making Ornamental Trees Edible

Street Re-View: Hacking Google with Theatrical Performances

Abandoned Bridge Amphitheater Reclaims Public Space

There’s no missing cyclists – or the zone of space you need to safely pass them – when they’ve got a ring of red light encircling them as they ride down the road. Michelin’s new open-source project, Bikesphere, features a light sensor and proximity detecting sensor that work together to monitor the environment around a cyclist and react accordingly if a car gets too close, pointing a double laser spotlight on the ground to define a safety area.

As it stands, riding a bike in an urban area can be a risky proposition, with more than 5,000 avoidable accidents happening every year due to cars passing cyclists at an unsafe distance.

During the day, the Bikesphere works like a normal light-detecting bike lamp, turning on when you go through dark areas as needed. By night, it’s ready to defend you, projecting a single-lined sphere for the entirety of your ride. When it can tell a car is coming, the light turns into a double line and starts to spin faster to alert both the cyclist and the driver.

Bikesphere is the first crowd-sourced idea to come to fruition through Michelin’s #TrendyDrivers movement, which aims to change the habits of drivers to make the roads safer. When an idea is approved, they fund the project to get it off the ground. Ultimately, the Bikesphere will be made public, so anyone who wants one can purchase the common components and download the plans to print the rest using standard 3D printers.

More than the sum of its parts, the conceptual swappable-piece mobile phone design that went viral but is now being backed by Google-owned Motorola and is suddenly much closer to becoming a reality. Instead of recycling your cell, imagine switching in new pieces as needed to customize, repair and upgrade the same device indefinitely.

Dutch design student  Dave Hakkens set off a chain reaction when he released his initial concept video online featuring Phonebloks, a simple but powerful idea for future-proofing mobile phones and creating an open ecosystem around such devices.

Motorola, meanwhile, was already working on a free, open-hardware device (think: Android for physical objects) along similar lines, and have now teamed up with this suddenly-famous designer. Like app makers in the digital marketplace, developers of physical components can make their own puzzle-piece parts for the devices.

Thunderclap helped Hakkens reach a huge audience quickly, with fans lending their social reach to promote the idea. Engineers, technicians and designers around the world showed interest in Hakkens’ design immediately as he racked up tens of millions of video views. He then began shopping around for partners to work on the project.

For its part in the partnership, Motorola brings technological research, experimentation and expertise to the table. In turn, Hakkens has built a huge fan following, showing his ability as innovator, designer and marketer.

Project Ara, Motorola’s name for the overarching and ongoing project, will be deployed along the same lines as Google Glass to beta testers. The first Phonebloks will be released to a limited audience who will in turn provide suggestions and feedback on the devices.

Worried about the end of the world? A group of engineers has created a series of do-it-yourself machines for building (or reconstructing) society anywhere with access to light, water and soil.

At eight times cheaper than their retail counterparts, these forty gadgets by Open Source Ecology are a globally-accessible alternative for disaster preppers and engineering geeks alike.

Think of them like large-scale LEGOs – the fewest necessary interchangeable parts required to construct essential wells for habitation, basic agricultural equipment for food production, steam engines for energy, 3D scanners and printers for industry and more.

“Open Source Ecology is accelerating the growth of the next economy – the Open Source Economy – an economy that optimizes both production and distribution – while promoting environmental regeneration and social justice. We are building the Global Village Construction Set. This is a high-performance, modular, do-it-yourself, low-cost platform – that allows for the easy fabrication of the 50 different industrial machines that it takes – to build a small, sustainable civilization with modern comforts.”