54
$\begingroup$

A common trope across multiple mediums and genres is roofhopping (WARNING! Tv Tropes), where individuals are seen rapidly running and jumping between buildings as a form of travel. For the setting, consider Generic City, a sprawling metropolitan area. On the same block, buildings are 10–24 ft (~3–7 m) apart. Most roads in the area are 2–4 lane streets. Building heights can vary some, but often not by more than 1–2 stories. Most permanent structures on the sides of buildings are fire escapes and garbage chutes.

Many times, the individuals involved have some sort of superhuman abilities. What I would like to know is, for a normal human being, is roofhopping in Generic City possible and could it be quicker than simply running on the ground? If so, why? If not, what would need to be changed about the infrastructure of Generic City for it to be possible/feasible?

$\endgroup$
  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – Serban Tanasa Sep 1 '16 at 13:22
  • 2
    $\begingroup$ Google "freerunning roof". Videos will come up. People are doing this. Not all cities look like American cities, and not all roofs are brittle. E.g. youtube.com/results?search_query=freerunning+roof $\endgroup$ – user8976 Sep 21 '16 at 14:05

11 Answers 11

61
$\begingroup$

It’s not possible to the extent you’re hoping for.

Most modern urban areas have a fairly consistent pattern in which buildings are broken up into blocks of various dimensions and separated by roads. Within a particular block many buildings are divided by small alleys (often to accommodate fire escapes). In my experience in Manhattan, these tend to be between 5 and 8 feet wide, but can change depending on whether you’re on a primarily commercial or residential block.

The roads that break up the blocks vary in number of lanes, sidewalk width, bike lanes, and other features, but the smallest urban road is typically a one-way street that is wide enough for parked cars on at least one side of the road and one lane of through traffic. A vehicle lane is typically about 10 feet wide, but an additional 5-10 feet is usually provided to allow for street-side parking. An additional width of at least 5 feet is sometimes allocated for a bike lane, and then you also have to consider sidewalks. And remember, these are the smallest one-way streets — an avenue is much, much wider.

The guinness world record for the longest standing jump (achieved via parkour) was 10 feet 4 inches (3.15 meters).

Looking at the distances above, a skilled parkour jumper should be able to jump between buildings of comparable height within a city block, but would have very little hope of jumping between street blocks. Height, however, is of major significance. Without consistent grips on the side of a building, jumping from a shorter building to a taller one may not be feasible. Likewise, if the height difference is too great, you may not be able to safely jump from the taller to the shorter. As the below image of Manhattan will show you, building height varies drastically even in height-restricted areas free of skyscrapers. All it takes is a height difference of 2-3 stories to make a transition slow at best and impossible at worst.

enter image description here

Even under ideal conditions, the speed of traversal is unlikely to be better than running on the road or sidewalk unless your start and end points are on rooftops. Rooftops are rarely flat and often have structures or objects on them that will impede your progress. Long distance jumps also require a good deal of energy, and performing many of them in short succession may be more exhausting than simply running at a constant speed at street level. When you throw in the reality that wider avenues are commonplace, your rooftop traversal will simply be interrupted too often.

As a final note, even games that feature parkour prominently in clustered urban areas (such as Mirror’s Edge or the Assassin’s Creed franchise) make it clear that jumping between “blocks” simply isn’t feasible. To get around that, they use environment props such as wooden beams, tight ropes, or zip lines to cross roads. Wall grips are everywhere, even where they make little logical sense. Buildings with major height differences have soft landing zones to enable a jump from dangerous heights. Building heights are more-or-less uniform and wide avenues are rare. Looking to these cities, which were literally designed to make rooftop parkour possible, is a good way to inform parkour-friendly city design. Be aware, however, that these games don't truly take runner fatigue into account. Scaling buildings requires a great deal of effort, which means uniform building height would be much more important.

$\endgroup$
  • 1
    $\begingroup$ Also check out "Vector" phone app game. Fun, but fairly implausible jumps and drops are staple. I would say it depends on your setting - if you are going for heroic, then yes, absolutely. If you are going for realism, then no, not so likely, unless your city is built differently than modern ones. $\endgroup$ – nijineko Aug 29 '16 at 15:55
  • 6
    $\begingroup$ For leaps across wide spaces, drops of 1 or 2 stories are actually ideal... $\endgroup$ – Rory Alsop Aug 29 '16 at 16:58
  • 3
    $\begingroup$ This might be made a bit easier in cities on a slope traveling in the downhill direction. Since each roof is a bit lower (but not leg-breakingly) lower than the one before it, it might be more feasible than running if you are going downhill and the streets are otherwise twisty/turny (perhaps switchbacks to help carts/cars navigate the slopes). This doesn't really enable getting back that way, though, but works for a one way chase scene. $\endgroup$ – Ethan Aug 29 '16 at 19:14
  • 4
    $\begingroup$ Washington DC would also not allow much roof-to-roof jumping. At the same time, my brief experience in Venice, Italy leads me to believe that not all cities are equal in this regard. European cities in particular, with many roads predating the invention of automobiles, may have many extremely narrow streets and closely crowded buildings. In general, I agree to that you can't go far on rooftops in most cities, but there may be some old world cities where it is much easier. $\endgroup$ – Todd Wilcox Aug 30 '16 at 0:38
  • 20
    $\begingroup$ As European I can tell: This concept of "blocks" is virtually unknown here. In some parts of the planned cities of Eastern Germany it happens, but even there its seldom and looks odd. So, this answer considers only "modern American urban areas" and is not applicable elsewhere. $\endgroup$ – Angelo Fuchs Aug 30 '16 at 7:38
25
$\begingroup$

In many fantasy cities (and some historic) upper floors of buildings are often built wider than the lower floors because real-estate is at premium. In some cases buildings might meet above a street (or come close enough to be easily jumpable).

If you want rooftop parkour to be a thing, just take the above premise and run with it; even for a present day/futuristic setting, roof-running might be feasible in historic districts, while fresh development areas are not so accessible.

$\endgroup$
  • 2
    $\begingroup$ The point about having upper floors wider than lower floors is great. Today's cities do not permit this usually, but it is not out of the realm of possibility. Coupled with Avernium's answer that existing cities do not permit it, we have a good answer to the question. +1 to both. $\endgroup$ – Ross Millikan Aug 30 '16 at 2:58
  • 1
    $\begingroup$ Watch out for the strength of roof construction in these scenarios. They may (not will, might) be strong enough to walk on. But even that doesn't mean that they will consistently support landings as you move from roof to roof. The material cost of building in strong materials is often prohibitive in these environments, so the spacing and strength of materials used will be the minimum that will survive the weather. $\endgroup$ – dmckee Aug 30 '16 at 18:57
  • 1
    $\begingroup$ It definitely depends on the city. Cities with organized grids and blocks were usually built or rebuilt recently. Older cities weren't necessarily designed with cars in mind, and may have buildings quite close together. A decent chunk of those were designed with the roof as very much part of the house (search "pueblo" for a striking example.) So the "strength" argument varies as well. $\endgroup$ – SirTechSpec Aug 30 '16 at 21:36
  • $\begingroup$ They are also a thing in modern day life - greedy developers will build it if it gets them more top-floor revenue, no matter how ugly $\endgroup$ – gbjbaanb Sep 1 '16 at 7:31
  • $\begingroup$ Other examples of old and new buildings with this feature: commons.wikimedia.org/wiki/File:TroyesRuelleDesChats.jpg commons.wikimedia.org/wiki/File:Motoazabu_Hills.JPG commons.wikimedia.org/wiki/… $\endgroup$ – Nicolas Raoul Sep 1 '16 at 8:29
22
$\begingroup$

The best place for roof-hopping would be a slum - I have Dharavi (Mumbai) in mind, but I believe this can work in other such areas as well. These slums are unplanned or semi-planned areas in urban agglomerations with very narrow streets, and individually-built structures which are not uniform, but typically have the same number of storeys.

Dharavi Slums

Chasing someone through such an area at street level would result in innumerable collisions and a quick end to the chase. However because the structures roofs are more or less aligned (with some dramatic exceptions), it makes more sense for the chased person to take to the rooftops.

Such rooftops are built strong enough to take the load of multiple people, and torrential rain.

Indians partying on rooftop Kite flying on Indian Rooftop - Pic copyright The Hindu

$\endgroup$
  • 12
    $\begingroup$ Chasing someone on those roofs may very well end with you in someone's kitchen with a broken leg after you fell through! $\endgroup$ – Steve Mangiameli Aug 30 '16 at 21:14
  • 4
    $\begingroup$ You need to wear something like snowshoes to spread the load while doing it. $\endgroup$ – JDługosz Aug 31 '16 at 7:27
  • 1
    $\begingroup$ This goes back to my comment above. Those roofs will only be strong enough to support the weight of the corrugated sheet or tiles, not a running/jumping person. Your chances of getting any distance are virtually zero. $\endgroup$ – Graham Aug 31 '16 at 9:19
  • 3
    $\begingroup$ Kids regularly fly kites off those rooftops, and I even added a pic of multiple people standing on a roof like that. The construction is typically red brick + mortar load-bearing walls, with steel I-beams to support the roof. Multistorey ones will have RCC slabs as well. These are serious houses built for monsoon areas, almost all with TV and Fridges and a few with air conditioning as well. The "mangalore" clay tiles are only placed atop the aluminium roof for heat insulation against the hot sun. $\endgroup$ – Pranab Sep 3 '16 at 7:45
16
$\begingroup$

Several people have mentioned Assassin's Creed and other similar games featuring older houses in cities with narrow alleyways. The film Crouching Tiger, Hidden Dragon also showed people running across rooftops.

It's a nice idea. The trouble is that roofs simply aren't designed to take the kind of point weights that you get from an adult landing heavily on one foot. If you stick to the ridges then you can probably get along, but if you tread on the roof itself without crawling boards then an adult is very likely to go straight through. They're only designed to take enough weight to allow for distributed pressure such as snow - and in areas with heavy snowfall you see much steeper roof pitches to reduce that load. Even for sticking to the ridges, they're not intended to take the point weight of a falling person.

So your medieval parkour specialist would be fine until they had to jump across their first street. On landing, they'd go straight through the tiles/shingles/thatch and land heavily in the room/attic below. The chaser simply has to nip down to ground level, go in the front door, and remove the parkour specialist on a stretcher.

$\endgroup$
  • $\begingroup$ This. Though thatch in particular can be pretty strong if they use a lot and the rods it is tied on are thick enough. $\endgroup$ – dmckee Aug 30 '16 at 19:07
  • $\begingroup$ @dmckee Though how easy is it to run on a thatch roof (especially a sloped one) compared to the street below? $\endgroup$ – Dronz Aug 30 '16 at 21:46
  • $\begingroup$ I would think it would be treacherous at best. $\endgroup$ – dmckee Aug 30 '16 at 23:02
  • 1
    $\begingroup$ In some contries (e.g. Greece) it is apparently common to build to a certain height, then continue years later when there is more money and/or more need for space. In the meantime the building would have a solid floor for a roof, often with rebars sticking out at the corners in anticipation of the next storey. See e.g. this image or this. Common use of this approach might make roofs more suitable for such a story, at the cost of less uniform heights. $\endgroup$ – MvG Aug 31 '16 at 20:35
  • $\begingroup$ @MvG That's broadly true for new houses in Greece. (Unfinished buildings didn't get taxed the same, so Greeks left their buildings unfinished. Just one reason why Greece is bankrupt - but that's another thread.) Older houses do tend to be finished though. And when you're in a city, houses are mostly finished because they're older, so again you have the roof strength problem, and of course road width. Of course you can get a long way in an old town full of small houses by hopping over walls through backyards/gardens, but that's just shortcuts at ground-level (or at most first-storey). $\endgroup$ – Graham Sep 1 '16 at 9:46
14
$\begingroup$

Yes it's possible

Parkour This is actually a real sport. People can train to do seemingly inhuman feats like falling from 10–15 feet uninjured in real life.You should go look for some parkour videos and their stunts, it's ridiculous and entertaining for me. While I'm not clear of how NYC layout is, it should be entirely possible to parkour across roofs. Whether it's faster than running on the ground is debatable. Running on the ground would usually be faster if there are no obstacles like giant roads choked with cars at 50–60 miles a hour. Running on roofs could allow a person to skip these ground obstacles but if the gap between roofs is too big...

How to improve the city for parkour

Have you seen Mirror's edge? It's a game about parkour basically, I recommend checking it out. To have a city conducive for parkour, we would need it to have plenty of pipes that allow climbing, zip lining ropes, closely packed buildings, lots of scaffolding and climbable walls. This would allow a skilled and experienced parkourer to traverse across the city easily.

$\endgroup$
  • 19
    $\begingroup$ Parkour is really cool but it is not improvised. Its in the name, you have to learn the road before starting to Parkour and you improve the run each time you do it. You can't just go through the city. And it's not very fast compared to walking in the street and its exhausting. $\endgroup$ – Rigop Aug 29 '16 at 13:00
  • $\begingroup$ @Rigop that's true, mistakes are prone to happen. But no one really knows whether someone would get across a city block faster by running or by parkour, there are plenty of environmental factors, that person's physical capability and on and on. I kinda think running is faster tho, level ground, no concern for dieing(unless you trip fall and smash your skull against the pavement) and you would win 10 out of 10 if it's a straight line. $\endgroup$ – Skye Aug 29 '16 at 13:07
  • 5
    $\begingroup$ An other factor is the risk. Athlete get injured often just doing standard training in controlled area. Running in non-controlled area is very risky. If the weather is rainy just forget it, its too slippery. $\endgroup$ – Rigop Aug 29 '16 at 13:18
  • 1
    $\begingroup$ 50-60mph in a city(NYC) is unrealistic, maybe 30mph.... $\endgroup$ – depperm Aug 29 '16 at 13:54
  • 6
    $\begingroup$ Iirc 3m is about the limit even the best parkourists can jump and still land on their feet, so unless the other building is a story or 2 lower theyre probably not jumping across streets. While they can fall 10-15ft down witouth immediate injury, they don't like to do it very often because they know it puts a huge stress on their body which can accumulate. Finally, as Rigpop pointed out, whenever you see cool parkour videos they are always planned out in advance, obstacles checked if they are slippery, if the object is loose, etc. $\endgroup$ – Ovi Aug 29 '16 at 14:08
6
$\begingroup$

for a normal human being, is roofhopping in Generic City possible and could it be quicker than simply running on the ground?

Possible, yes. The trick here is that you would not be able to take direct route. You may be able to get from 1st to 55th street via rooftop, but you may have to go across 100 streets to do it. For example getting from 2nd to 3rd directly may not be possible, but you could go a few blocks on 2nd to a pipe that sticks out, and then get over to 3rd, but then have to go 5 block back to find another spot to cross to 4th. You would need to know the city very very well, but it is possible.

Faster, no. What makes it possible is that you can travel from point a to b by knowing where some short cuts are, even if those shortcuts are 1-2 miles out of the way. It's always going to be better to go in a straight line. Now if you could not take the road, then roof top access may be faster. But your basically saying that running on the tops of buildings is faster then not moving at all.

what would need to be changed about the infrastructure of Generic City for it to be possible/feasible?

In Tampa FL, and Grand Rapids MI at least a few buildings already do this. I am sure other cities do as well. They create walkways between buildings. If your city had a lot of these walk ways you could maybe get faster via rooftop then by road. I remember an area in Grand Rapids where the roofs of buildings were actually made into a kind of park. You wouldn't even know you were on a roof top. If these roof top parks were connected then you would get a pretty straight line.

$\endgroup$
  • $\begingroup$ FYI these between building accesses are generally not roof level. $\endgroup$ – coteyr Aug 29 '16 at 22:30
4
$\begingroup$

Roofhopping or Parkour is a sport made to look cool. It gives you a better vertical speed, you may win against someone running up stairs (or maybe not depending of his condition). But the horizontal is not magic, you jump obstacles the fastest way possible but you could just have chosen a better way at the beginning.

A normal human doesn't have the strength, the agility and the cold blood to execute the most basics move. It is not an accessible sport, it require a lot of skill and training. You have to practice in safe place hours before trying moves in dangerous place unless you want to die young.

Also you expose yourself to multiple injuries and you risk your life.

Le Parkour is an extreme sport, it will never be widely practice and it is not a safe way to travel.

$\endgroup$
4
$\begingroup$

"for a normal human being, is roofhopping in Generic City possible and could it be quicker than simply running on the ground?"

No, only in specific places where the buildings are conveniently arranged for that. Or in non-generic-modern-US cities, where in some cases it's more common for the buildings to be conveniently arranged for that.

Could it be quicker? Not generally but yes, in some cases it could be. There might be a lot of traffic on the ground, or you might be trying to go in directions that the streets don't go. The real advantage tends to be in terms of avoiding detection and escaping pursuit (so while it's not faster than you running in the street, it may make you faster than others), because:

  • Usually rooftops are mostly or completely blocked from vision from below, so surface pursuers won't know where you are or which way you are running.
  • Usually getting up to catch you involves time-consuming and possibly blocked passages through unknown buildings to reach the roof.
  • Someone choosing to run and jump across roofs is either foolhardy or has some exceptional skill/practice in doing so, so many other less foolish/crazy or skilled pursuers may stop, slow down, and/or fall.
  • Someone choosing roof travel may have studied the roofs in that location in advance, and have a path they know about that their pursuit does not.
  • If violence is part of your plan of action, there may be fewer witnesses if you are doing something like resisting arrest on rooftop, as opposed to down on the streets where most witnesses are.
$\endgroup$
2
$\begingroup$

I have a bit of personal experience with this and it's viable (with some important restrictions). Most importantly, no normal human will be able to jump a 2 lane road.

When a block is laid out with buildings touching each other it's trivial to make your way down the row without touching the ground. It's not even too hard to make up the difference in height. Of course down is easier than up, but it's not hard to find a way and there's nothing like someone chasing you to inspire a bit of creativity. (In another situation I once vaulted a 6 foot fence at a dead run using one hand and a bit of canine inspiration.) A little practice and a reasonable level of base fitness goes a long way. Knowing the area is also a huge bonus.

The main street in my hometown was like this and we used to think it was fun to make our way down the whole block this way. There were several changes of height and multiple ways to make one's way up or down. In a situation where the streets are packed due to a festival or riot this is actually a quicker way to move around. It's also a nice feeling to be up away from the crowds and a good way to avoid anyone who might be searching the streets for you (not that I know about this part from experience, it just seems very peaceful up there and nobody ever seemed to look up)

Crossing streets presents the biggest problem. In theory it's possible to jump a narrow alley, especially if you get to go down one story, have a clear place to land and know how to roll. In practice I wouldn't count on it and I'd expect to sprain an ankle the first time you try it. Jumping a road that's too wide sounds like a great way to splat and die. Whenever you see someone do a jump like this in a movie it's either over a narrow alley or it's somebody with super strength.

I don't have personal experience with a tighter downtown design, but I've seen cities that look like they'd be way more amenable to rooftop shenanigans. Cities built in the middle ages had very narrow streets and many have preserved the old town as pedestrian-only shopping districts. Old town in Zurich is like this. Jumping the narrow pedestrian only alleys looks totally possible (though, when I visited I was much past the point in my life where I'd go try that out)

$\endgroup$
2
$\begingroup$

The debate about falling through the roof seems to have been resolved by earlier answers.

FloorboardFailureTrope (usefulness for furthering the storyline notwithstanding)

The real issue seems to be: What does it mean to be 'on the run' on rooftops, in terms of storytelling?
The high altitude financial district scenario is the elite version, requiring specialised skills for admission, similar to escaping by jumping in the water when the pursuer can't swim.

Hopping from one rooftop to another can force non-parkour types to run from the base of one elevator to the next in hopes of catching their quarry. Attacks from the ground seem unviable, but being 'herded' into a dead end [leap of faith trope] by aerial pursuit is a real danger. Inaccessibility comes at the price of limited avenues of escape, and insider knowledge of the terrain should determine who wins.

The mid-height scenario really only requires that both pursuer and quarry be relatively athletic and/or sufficiently desperate. Also this version is pretty much over-the-counter, in terms of not relying on crane operators or AC techs having left things in conveniently improbable configurations. Close proximity to the ground means that attacks from the ground may be viable, but allows for the option to segue the chase to ground level in a jam.

Downsides to this chase style is the total lack of street signs for directional cues, along for the likelihood of landmarks being obscured by nearby buildings. Long runs of brownstone flats, very narrow streets lined with mid-rise apartment projects, and the winding and tightly packed streets of European villas are all good examples. [Google James Bond Rome images]

The low-height variant involves street level essentially being the roofs of the buildings to start with. Basically being on ground level means crowds can be a big hindrance, random passersby could join in aid the pursuer(s) or quarry. The chase would start to resemble more of an obstacle course race, and allows for nearly infinite route improvisation.

Since it is difficult to be physically inaccessible, use of soft cover, misdirection, and confusion become much more prominent strategies. Favelas (Hulk 2008) are a good example, and Pranab's Dharavi pic up there ^, as well as several cities mentioned in the bible. Even some back alleys in Salvador change level so often as one restaurant back patio connects to the next that it would feel like a rooftop chase, even though it's technically ground level.

Çatalhöyük

Why should you have to pick just one? As long as you can argue the population density of Generic City is high enough, your rooftop chases could range all the way from the downtown core to the suburbs and back, if required.

$\endgroup$
1
$\begingroup$

Almost all the comments I've read have been about American cities, so let me give you the European perspective.

Short answer: Yes, kind of

Long answer: A lot of it depends on the city that your in. In rainy climates, roofs are slopping and this would make them more difficult to run across, especially if it has been raining recently. However, that doesn't mean it would be impossible. The popularity of fell running proves that running along slopes is possible, although dangerous.

One flaw people have pointed out are the roads that run between buildings. In American cities, this is a problem because you tend to have wide streets and a grid pattern to your city. However, in most other countries, streets are more sporadic so there is definitely an advantage to running along roofs to cut corners.

Basically, it takes practice and agility and would work best in cities with dense populations, narrower roads, low rainfall and you'd need quite specific circumstances to want to but yeah, it would work

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.