Showing posts with label design guidelines. Show all posts
Showing posts with label design guidelines. Show all posts

Wednesday, March 11, 2026

The problem isn't the underpass

Poor underpass design, placement and maintenance are only part of the problem

by Mateja Mihinjac

Few examples of pedestrian public infrastructure have as much potential to go wrong as pedestrian underpasses. Nearly every city I’ve visited has at least one that has become problematic.

I have blogged on this in the past such as underpass graffiti and homelessness. But the problem is bigger than that. The problem centres around participatory design and ongoing stewardship.

Underpasses can separate pedestrians from traffic, but many urban designers treat them as a last resort. New Zealand Transport Agency guidance notes that at-grade crossings are usually preferred because they keep pedestrians visible and the street active, which supports perceived safety.


Underpass in Ljubljana, Slovenia - a much too-common example of neglect and fear in underpasses around the world 


The tradeoff is predictable. Underpasses often feel isolated, attract neglect, and can be hard to use for older adults, people with disabilities, and parents with strollers.

Research on fear of crime consistently shows that enclosed pedestrian tunnels and underpasses can generate strong perceptions of danger when lighting, visibility, and maintenance are poor.

Because of these concerns, street design guidelines increasingly favour at-grade crossings such as raised crosswalks, traffic calming measures, and pedestrian-priority streets that keep pedestrians visible and integrated into everyday street activity.


A SENSE OF DISGUST & INFRASTRUCTURE LIABILITY

A few days ago I came across an article about one of the underpasses in Ljubljana that has been problematic for years. Recently, the city has decided to close it completely. The underpass runs beneath a busy arterial road and connects a large shopping mall with nearby residential buildings and local services. 

This pedestrian underpass in Ljubljana was built to protect people from traffic. Today, it is closed because it became unsafe to use. 

I remember using the underpass several times a few years ago. Each time I dreaded it. The tunnel was dark and smelled strongly of urine. One entrance was covered with graffiti tags. A section of the corridor was often flooded with stale smelly water. People loitered there for long periods. 

On one occasion a couple of years ago, a man in the underpass approached me asking if I offer “special services,” after saying he only wanted to ask me a question during my walk to the shopping mall. More than fear, the experience produced a sense of disgust — the feeling that this space had been abandoned by those responsible for managing it.


A closed underpass - why were problems allowed to grow in the first place?  


After years of decay, the city eventually closed the underpass completely. What makes the situation even more striking is that the tunnel sits next to one of the most prestigious residential developments in Ljubljana, currently the tallest building in the city.

The article reports the decision to close it came from “professional assessment of the current state of the infrastructure, safety risks and the sensibility of its continued use”. It also reports on people’s complaints concerning the homeless, faeces, urine, syringes, vandalism and rubbish that kept accumulating in the underpass. 

No decision has yet been made whether this closed underpass will eventually reopen. It raises questions: What engineers are responsible for this? Who are the decision-makers? What are they saying? How did they neglect this for so long? One can only imagine what conversations are going on behind closed doors. And that leads to the true problem- the design process! 


IT ISN’T THE UNDERPASS…IT’S THE PROCESS

When cities close infrastructure because it feels unsafe, something usually went wrong long before the first complaint. This is not simply about lighting failures or graffiti. It is about a system that failed to monitor, maintain, and adapt.

Some cities are beginning to recognise that infrastructure like pedestrian tunnels cannot be evaluated by engineers alone.


Steven Eisenhower bicycle Tunnel, Nijmegen, the Netherlands
- photo Steven Vance, CC BY 2.0 via Wikimedia Commons


A useful example comes from Toronto, where the Glen Road Pedestrian Bridge and Tunnel Environmental Assessment incorporated extensive public consultation. Community feedback helped identify safety concerns and guided improvements to ensure the infrastructure actually worked for those expected to use it.


PRACTICAL LESSONS LEARNED

From a CPTED and SafeGrowth perspective, the Ljubljana underpass displayed several familiar warning signs. Poor natural surveillance created hidden spaces, weak territorial reinforcement meant the area felt like it belonged to no one, and low activity levels reduced informal guardianship. Over time, maintenance declined and limited community engagement allowed problems to persist largely unnoticed.

None of these issues appeared overnight. They develop gradually as stewardship declines.

Modern CPTED guidance recognises that design alone cannot maintain safe places. Ongoing stewardship and community involvement are essential. Technical guidance such as the Queensland Transport and Main Roads Department’s underpass design guidelines provide useful direction.


Australian urban design guidelines developed by social planner Wendy Sarkissian


SafeGrowth engages residents and local users in diagnosing problems and shaping solutions. Community knowledge often identifies risks long before they appear in official reports. Without that feedback loop, infrastructure can slowly decay into places people avoid.

SafeGrowth emphasises participatory safety planning, where residents, practitioners, and local agencies discuss design and management issues together. In these processes, the social planning principles championed by social planner Wendy Sarkissian remain especially valuable. 

Pedestrian underpasses are not inherently unsafe but closing them may sometimes be necessary. The real question is why the problem was allowed to grow in the first place.

Safe cities do not maintain themselves. They depend on stewardship and the people who care enough to protect them.


Saturday, September 4, 2010

An incomplete equation

Clean, efficient design with great sightlines, yet empty streets.

I spoke to Elisabeth Miller, a planner friend from Saskatoon, this week who told me about the pending publication of some CPTED and Design Guidelines for developers and architects. She is a planner with the city of Saskatoon and last fall I researched and crafted these design guidelines, which Elisabeth and I then wrote into a Guideline document, from best practice around the world.

Could a similar approach work at a larger scale, for example in urban zoning?

If you study different types of zoning it is clear that most forms of zoning align with architectural design guidelines. Then I realized there is a problem with zoning.

In Death and Life of Great American Cities Jane Jacobs says, "No amount of police can enforce civilization where the normal, causal enforcement of it has broken down."

Jacobs used the ideas of territoriality and social capital as part of her equation for safe streets. Unfortunately early CPTED used only half of that equation - urban design.

As all new students of CPTED soon learn, basic 1st Generation CPTED involves urban design and architecture to reduce crime opportunities. There are three components:

1. We See You: Natural surveillance is lighting and landscaping that puts eyes on the street. The purpose is to see offenders or to signal to offenders they will be seen.

2. You Are In Our Place: Access control is gates, fences, roadway barriers, or walkway placement to limit the number of people into or out of an area. It allows people to see who is entering or to signal to visitors - we live/work here.

3. You Can't Get Away With That Here: Territorial reinforcement divides public space to semi-private or semi-public areas - for example, paving patterns and floral landscaping to demarcate a building entry. Clean-ups are another way to signal someone cares. These make it difficult for offenders to offend with impunity.

All three components hinge on one simple (and debatable) idea: It's our turf and we care. Design guidelines fit perfectly into this part of the equation. Zoning – not so much.

Here's the problem

In the absence of social capital, territoriality doesn't just happen. It is not necessarily true that people care simply because their space encourages it.

There are plenty of places where access control, good lighting, and natural surveillance provide a very poor sense of territory. Urban mega-projects like sports stadiums and casinos are notorious for plenty of crime (pick pocketing and robbery come to mind).

Large box stores are another example where there may be many eyes on those streets, all sorts of branding, signs, and territorial markers and yet crime can flourish (auto theft comes to mind).

Territoriality can help but it cannot ensure crime is absent. The intimate personal space of a residential living room or bedroom is already "owned" and controlled yet that is precisely where most domestic violence occurs.

The fact is territoriality does not work without social capital.

Next: How zoning can help.