futility, geometry, and action

To bypass the rage and righteousness around an issue, and move toward solving it, we first have to convince ourselves that solving it is impossible.

That's the thesis of Andrew Sullivan's piece today, "Why the Healthcare Question is Insoluble."  He's talking about healthcare in the US context, but few countries have achieved widespread contentment on the issue.  I'm not sure you can expect widespread contentment on an issue that requires thinking about sickness and death, at least not at humanity's current level of spiritual development.

My work on transit policy has always come from the same existential position that Andrew lays out.  Like every family working out its budget, societies have to make choices between different things that they value.  As in healthcare, arguments about these choices often use pre-emptive appeals to compassion or justice to shift our attention away from the the real choice.  Government actions that are "compassionate" or that address "civil rights" seem to be responding to an absolute standard of goodness and truth, but often, they still cost money, possibly more money than any government can expect to spend.

I'm very glad to be in transit instead of healthcare, because a few hours debating healthcare makes transit problems look easy.  Easy, but still impossible

By easy that I mean that the questions are relatively easy to frame (Connections or complexity?  Ridership or coverage?  Wide stop spacing or close?) and it's not too hard to explain (a) the consequence of each choice and (b) why the choice is geometrically unavoidable.  Laying out those questions is a key task of my book Human Transit

But once you lay out those questions, you have to pause and see that by their nature, there's no answer that everyone will like.  There may not even be an answer that a majority will like.  And in that sense, the task of resolving the issue is impossible

The geometry of transit tells us that each of these choices gives us a spectrum of possibilities.  A transit network can go to the extreme of relying on connections, and thus minimizing complexity, or it can go to the extreme of avoiding connections, which maximizes complexity, but every time you move toward one desired outcome, you move away from another one.  That's how a spectrum works.  And you can appeal to "civil rights" or "compassion" or "common sense" or "the needs of working families" as much as you want; those appeals may prod policymakers to move one way or the other, but they don't change the geometry.  In fact, they're dangerous to the degree that they encourage us not to notice what has to be sacrificed to move in the direction that the speaker advocates.

My experience with many transit agencies is that everyone is a little scared of stating these questions in such a simple way, because it means you really have to answer them.  And answering them requires accepting, with some humility, that any possible decision will leave many people outraged.  Faced with the courage that this requires, it's tempting to retreat into the confusion.  It's tempting to want the issue to be complicated so that you'll never be called to account for making a clear, stark choice of this over that — even though true leadership lies exactly in the willingness to make those choices.  So when an issue seems complicated, we always need to ask, "what interests are being served by the sheer complexity of this issue?"  "Can the issue actually be made simple?"

I'm not sure that can be done for healthcare, but bravo to Andrew Sullivan for trying.  I am pretty sure it can be done for many of the main debates in transit policy, and that's the core of my work right now.

comments of the week: ideal stop spacing is 400m?

Zoltán:

My experiences in Leeds and Baltimore confirm the validity of a 400m standard for stop spacing. Rarely do you get to experiment with reducing or increasing stop spacing, but we can look at the sum of the experience of the two cities.

In Leeds, there have been a number of routes, normally small single-deck buses running every 30-60 minutes, that have stopped frequently and taken local roads to penetrate various neighbourhoods better than the frequent, relatively fast buses on the main arterials.

These have pretty much all disappeared with time, because people always proved willing to walk about 400m to the main arterials, which is about the furthest you're ever expected to. My experience of occasionally catching one of the slower local routes is that I would be the only passenger.

So, this demonstrates that people really are willing to walk to speed and frequency.

Meanwhile, in Baltimore, buses do stick to the main arterials. But they stop at every corner, just like the streetcars before them, which in Baltimore is about every 120 metres. And hell, are they slow – from Catonsville, MD to downtown Baltimore, I frequently spent 50 minutes to an hour to travel 8 miles that can be driven in about 20 minutes.

What's more, it's an uncomfortable ride, because the bus pulls violently to the corner at every corner, to keep the hell out of the way of traffic. And that's actually the problem with the frequent stops in Baltimore – while boarding time is a bit more complicated (though there's a fixed element to people getting up and making their way out of the bus, and people waiting for the driver's nod to start boarding), you can basically multiply the time spent waiting to pull out back into traffic by the number of stops.

So what you have is a slow service, and by that virtue, a less frequent service, because one bus can make fewer trips. So, if people will walk to speed and frequency where delivered by different routes, then we can assume that people will also walk to speed and frequency on existing routes when that's achieved by means of widely spaced stops.

In thinking about this sexless but profoundly consequential issue, you may want to refer back to this post, which clarifies the concepts of coverage gaps and duplicate coverage areas.  (See that post for more explanation of this figure.)

Slide2

Balancing these two considerations is the essence of the stop spacing task.  Closer stop spacing means smaller coverage gaps but more wasteful duplication of coverage area.  So a lot depends on the local land use.  If there's more stuff along the transit corridor than in the coverage gaps, that argues for pushing stops wider.

The European HiTrans guides suggest 600m for stop spacing in busy areas where demand is high and local access is the intent.  In general, Europeans and Australians are willing to go wider than North Americans in a similar setting. 

So why on earth does any transit agency that aims to compete with cars put stops as close as 120m??  Well, these things creep up on you.  If ridership is so low that you won't be stopping at every stop anyway, close spacing doesn't present much of a problem.  But once ridership reaches the level where you're stopping at every stop, close spacing requires you to stop more, and thus run more slowly, to serve the same number of people. 

On the tradition of very-close North American spacing, John offered an interesting speculation:

"But right now, a lot of transit (in North America especially) seems designed to compete with walking, rather than with the car. Do we have the balance right?"

I think the balance is off, and I think it's largely a legacy of the streetcar era, when transit only needed to be faster than walking to draw a huge mode share. In that situation, minimizing walking distance made sense. Then the competition changed when cars came along and average trip distances increased. The streetcars were removed, but nobody ever bothered to change the stop spacing. Now transit isn't time-competitive, and in most cities it serves only the transit-dependent and niche markets like express routes to the CBD.

Is very close stop spacing on North American bus systems really so old that it predates the car, and therefore reflects the competitive situation between transit and its alternatives as it was around 1910?  That would be some sort of record for failure to adapt: a habit that has survived for an entire century after its obsolescence. 

Obviously, too, many North American services aren't trying to compete with the car; they're social services intended only for the transit dependent, and in those cases travel time is presumed to travel less.  But be careful about taking that attitude too far.

dissent of the week: stop spacing and transit’s multiple goals

Ben Smith from Toronto defends closely-spaced stops, on my post on imagining cities without mobility, which suggests the need to focus more on widely-spaced "rapid transit" stops. 

I'd like to be the devil's advocate for a minute and defend somewhat tighter stop spacing. Think of transit as an elevator: You're on the 7th floor and decide to walk up to the 8th floor, and feel that having the elevator stop there is a waste. However, someone who is getting on at the ground floor may also want to get off at the 8th floor, so having a stop there isn't a waste.

I'm not trying to say that transit should stop at everyone's doorstop, but there is a case for having a more local oriented transit with SOMEWHAT frequent stops. However, if demand and density is having your transit vehicle stop every 100m with a large number of passengers boarding at each stop, then it makes sense to use a higher-order transit vehicle with wider stops.

The easy answer to this is that if you can walk from the 7th floor to the 8th floor to get from one to the other, you can take the same walk from an express elevator that stops only at the 7th.  But that may be too easy. 

I personally am willing to walk as far to useful rapid transit (for a long trip across the region) as I will to a final destination.   My personal mode choice algorithm (as far as I understand it) is that I want to (a) minimize total travel time and also (b) get exercise and (c) avoid waiting and especially passive uncertainty.   So I'm as willing to walk the same distance to a place regardless of whether that place is my destination or I'm planning to catch rapid transit there.

Does my philosphical viewpoint on this depend too much on my own abilities and preferences?  In other words, am I assuming that secretly everyone wants to be just like me?  And if so, am I doing this more than anyone else does?

Obviously, as always, we need to recognize a portion of the population that can't walk far, but at the same time we have two widely articulated policy goals that push the other way:

  1. health goals that support encouraging people to walk if they can. 
  2. sustainability goals that require transit with highways rather than with walking and cycling, which means competing for the trip that is well beyond most people's walking distance

Those considerations lead me to a provisional view that the main prioirty for public transit investment needs to be rapid transit that's worth walking to, not slow transit that stops near everyone's door and that looks intimate and friendly in a New Urbanist mainstreet.  That was the core of my argument with Patrick Condon.

Obviously, there need to be mobility options for senior and disabled persons who have greater need for short-distance transit.  There are also other logical markets for short-distance trips where very high frequency is possible (recalling that waiting time is often the disincentive for short trips) such as downtown shuttles. 

But right now, a lot of transit (in North America especially) seems designed to compete with walking, rather than with the car.  Do we have the balance right?

UPDATE!  Ben Smith, the author of the dissent, has had an epiphany!

beyond grey

San Francisco's Bay Area Rapid Transit system (BART) is, let's be frank, extremely grey.  Most of its above-ground stations feature vast expanses of exposed concrete, true to the prevailing modernism of the age.  (Most of the system was designed in the 1960s.)

At stations like MacArthur, where the grey station infrastructure interacts with the surround grey ramps of the freeways, one can wonder if the original BART planners were so obsessed with competing with freeways that they deliberately chose freeway-like lines and colors, especially where real freeways were nearby.  This, of course, would be competition by resemblence rather than by differentiation.  At one stage, that probably made sense.

And yes, cool grey can be beautiful, but only if there's color to throw it into relief.  Modernism sometimes drew encouragement from the coolness of classical Greek and Roman architecture, but of course the ancient world seems colorless to us only because paints, fabrics, and other vehicles of color don't survive the centuries. 

So it was fun to open my mail this morning and find this painting by Alfred Twu, reimagining the freeway-dominated landscape of MacArthur BART station with a more tropical sense of color.  Why must we go to Germany to see bright colors and strong choices in design?

MacArthur_BART_1024

UPDATE:  I can't resist highlighting a comment from jfruh:

I always think that BART is what someone in 1969 thought the future was going to look like.

If you're too young to remember 1969, I strongly recommend reviewing Stanley Kubrick's great film 2001: A Space Odyssey (1970).  When I rode BART for the first time in 1976, I felt like I had arrived in the world of that film. 

station design and virtuous society

Does the experience of gaining altitude cause people to behave less selfishly?  David Schroeder in Scientific American profiles a recent study by Professor Larry Sanna of the University of North Carolina:

Building on research showing the power of metaphors to shape our thinking, Sanna and his colleagues noted that height is often used as a metaphor for virtue: moral high ground, God on high, looking up to good people, etc. If people were primed to think about height, they wondered, might people be more virtuous?

In a series of four different studies, the authors found consistent support for their predictions. In the first study they found that twice as many mall shoppers who had just ridden an up escalator contributed to the Salvation Army than shoppers who had just ridden the down escalator. In a second study, participants who had been taken up a short flight of stairs to an auditorium stage to complete a series of questionnaires volunteered more than 50 percent more of their time than participants who had been led down to the orchestra pit.

The link between elevation and virtue, of course, is an ancient idea.  It's why universities are so often on hilltops, despite the problems this presents for cycling and often for transit.

But this specific research reminds me of my old post on the difference between end-stations and through-stations, and my visceral dislike of stations that require arriving passengers to go down into tunnels under the platform.  I far prefer those, like Melbourne's Southern Cross or Calatrava's Liège Guillemins, where arrival involves climbing an escalator to a bridge-like concourse.  The real virtue of those stations, of course, is that you are continuously in the same space throughout the arrival experience, while a conventional through-station is inevitably two different spaces — the train shed and the arrivals hall — connected by tunnels.  End-stations, of course, achieve the same thing by not requiring a change of level at all.

My question of Professor Sanna's work would be whether it matters that you are in a continuous space throughout a change of elevation, as you are in the Melbourne and Liège stations, as opposed to being transported from one space into another, as you are in the typical escalator or stair connecting platforms to an underground passage.  I get no sensations of elevation when rising from one room into another, whereas I do from climbing within a single large space. 

(via Andrew Sullivan)

in vancouver

MEMO0006 I've arrived in Vancouver, and will be starting in my new part-time role with the transit agency, Translink, on Tuesday. At the moment I'm preoccupied with looking for housing for this six-month stay.  Home is so important to me that when I don't have one, it's hard to focus on anything else.  So between that and the book, my posts may be light for few days.

Meanwhile, if your city is on a river or very calm harbour, you should know about the micro-ferries of Vancouver's False Creek.  They're the smallest-scale passenger ferries I've seen in the developed world.  They carry 12 passengers on a perimeter bench while the single operator sits in the center and handles driving, docking, and fares.

They're ideal for short runs at high frequency over calm water, which is what they do.  More on them soon.

transit acceleration campaign goes national

For over a year now, Los Angeles Mayor Antonio Villaraigosa has been spearheading a "30/10" initiative, designed to accelerate the construction a range of urgently needed transit projects (mostly rail transit lines).  The key word is accelerate, not fund.  The projects are already funded, but on a 30-year timeline.  The 30/10 proposal would deliver the projects in 10 years.

The idea begins with Measure R, a 30-year sales tax increment approved by Los Angeles County voters in 2008 to fund a large package of rail transit improvements, including the Wilshire subway to the westside.  Villairagosa wants the Federal government to create a mechanism to bond this revenue so that it can be spent in one decade instead of three. 

Well, you can only get Congress interested if the same idea can be applied in many places, so predictably the Mayor and Metro are now presenting America Fast Forward, a national campaign to create a similar mechanism for any urban region that has already put funded projects in place.  Los Angeles Metro's blog Source covers it here, the Los Angeles Times's Tim Rutten opines here.  Here's a puffy PDF.

Because it relies on Federal financing rather than spending, and because the funding sources are local tax streams that are relatively stable, it's an approach that could potentially succeed even in lean times.

In a tweet, Cap'n Transit asked me:  Could it be used to build highways?  Yes, it looks like the same mechanism could be used, in theory, to fund any locally supported infrastructure.  I hope it will be constrained to transportation, and if it were constrained to voter-approved funding streams like Los Angeles's Measure R it could well usher in a new era of these measures, in which most voters could vote up or down on a set of plans knowing that if passed, all of them would be built and running in just ten years, soon enough to affect most voters' lives.

 

vancouver: new round of broadway line options

The planning for the missing link in Vancouver's transit network has taken the next step. Newly refined options are out for public comment.  The corridor corresponds, at least in its endpoints, to the orange line on this map, where the existing Line 99 runs one of the most frequent and crowded bus corridors in the west.

VancouverGrid(2) The west end is the University of British Columbia (UBC).  The east end is Commercial/Broadway station, the main transit gateway to the entire eastern two thirds of the region.  In the middle is Vancouver's second downtown, Central Broadway, which includes City Hall and the main hospital, as well as a station on the Canada Line to the airport and the southern suburbs.  (Skytrain and the Canada Line form the region's driverless rapid transit network.)  It's hard to overestimate how central this corridor is not just to the city, but to the region.  For example, many trips between southern suburbs and northeastern ones (Richmond to northern Burnaby say, or Coquitlam to the airport) will be made much easier, or not, depending on this project's outcome.

The newly refined options include rapid-transit options (widely presumed to be extensions of the Skytrain Millennium Line) either to UBC or possibly just to Arbutus Street, which makes sense to consider because it's the end of the dense or densifiable portion of Broadway, and completes all of the regional-connection needs except for UBC itself.  They also look at light rail options and Bus Rapid Transit, both of which would need an exclusive lane.  Light rail options are suggested both on Broadway and also veering off onto an alignment closer to False Creek, feeding into Great Northern Way.

It looks like an interesting process, one that will impact the transit mobility options for a vast part of greater Vancouver.

are toll lanes “congestion pricing”?

Congestion pricing should really be called decongestion pricing.  Its purpose is to provide an alternative to sitting in congestion for people and businesses willing to pay the fair price for the scarce road space required.  The toll isn't a tax, it's a price for driving in an uncongested lane.   So if your toll lane is still congested, you're not doing (de)congestion pricing, and your results say nothing about whether it's a good idea.

In Crosscut, former Washington State Secretary of Transportation Douglas MacDonald lays out the issue today as it applies to Seattle area freeways.  There, likely toll lanes are already High Occupancy Vehicle (HOV) lanes permitting cars with two or more people.  Everyone knows that if the goal is free flow, this minimum has to go up to three whenever congestion requires it. 

When carpool lanes were first established there was a vigorous “now or later” debate about the right limit for the carpool privilege: two-to-a-car, or three-to-a-car? Pragmatism won. Except for three-to-a-car from the start on the Evergreen Point Bridge, carpool lanes were introduced with the two-to-a-car rule.

Everyone involved at the time believed that later the rule would have to be, and could be, changed to three-to-a-car. Everyone was entirely up-front about this expectation. The trigger would be the growth of traffic in the carpool lanes to the point where access would have to be cut back so that they would still work.

Didn't happen. Good luck today with that ticking time bomb for a political revolt. The moment of truth is at hand, at least for some carpool lane segments. But no one today seriously talks about outright banishing the two-to-a-car carpoolers to thin out jammed carpool lanes.

I defer to Doug's knowledge of Washington State politics, but I do resist the apathy-inducing hyperbole of the phrase "no one talks seriously."  Is "everyone" sure that changing carpool lanes to 3+ would trigger a political revolt if it also caused people to start getting to work on time?  Especially if the state also put some effort into casual carpool facilities at the same time?  Especially if transit riders (in buses in the same lanes) began getting to work on time too?  I wonder.  I can see it would be controversial.  I can see it would take some time.  But can no one "seriously" discuss it?

connection-activated civic squares

A few days back I asked for examples of connection-activated civic squares, public squares that serve as both a symbolic and functional heart of the community, but where people connecting between transit lines form part of the square's activity.  I was looking for a real-world example of something like this, which is a design for a (non-existent) square in Surrey, an outer suburb of Vancouver:

  Surrey Central Plaza-1

The idea arises from the desire to have bus-rail connections happen in an interesting urban setting, rather than a typical suburban bus interchange that features an area where only bus passengers would be. 

First, I should answer this comment

Isn't the idea to reduce transfer penalties, not to deliberately increase them for other ends? Getting off the train on a cold, stormy night, I think I would resent being made to animate an otherwise deserted public square – running 200m for my bus, with my umbrella blown inside out, dodging puddles. Even worse if it was on the way to work in the morning!

Indeed it is.  I always want connection walking distances to be as short as possible.  The square above is 100m wide, so maximum walks would be no more than that, and that's not out of line compared to what you'll do in tunnels in many of the great subway systems of the world.  But I'm not sure that walking across a square is more onerous than walking along corridors or tunnels, so long as there's some reasonable alternative in bad weather.  And of course the urban designers are always telling us that visual interest makes walks feel shorter.  When walking along a typical subway tunnel lined with shops, I feel reduced to the status of consumer.  I would much rather walk across a square on a nice day.

One reason that these arrangements are unusual, and that I should have noted, is that they require buses to be organized in an inverted couplet.  In a country that drives on the right, you would expect that a westbound one-way street would be north of its eastbound partner.  That's the way two-way streets normally divide.  In this Surrey proposal, we set up the car traffic to do that but the buses to do the opposite in contraflow lanes.  That's how we got the bus stops to be on the square rather than across the street from it.  This is a great trick in situations where you already have one-way couplets of streets.  It gets buses out of traffic and puts them with their doors facing each other so that they can stop at opposite sides of a square (or even just at opposite ends of a pedestrian street or lane). 

(Portland's transit mall is a famous example of an inverted couplet — the northbound street is west of the southbound street — and if the Pioneer Courthouse Square were one block further east, it would be a spectacular example of a connection-activated square.  The mall couplet does help create an effective square at PSU Urban Center Plaza, where the mall and the streetcar intersect.)

It was quickly clear from the reader suggestions that really large connection-activated squares have to be in pretty big cities.  Even there, size can be a problem.  Note how Lyon's Place Bellecour, below, is reduced in width by a bit of landscaping.  The whole block is 250m x 170m, but the trees reduce the purely open space to about 100m wide.  At that, it's still the largest clear square in Europe, says Wikipedia.  There's room for two soccer fields in the remaining open space, three if that guy on the horse would get out of the way.

Place bellecour lyon

Place Bellecour does have a bus stop facing onto the square on the east side, but the main east-west bus movement is east on the south side, west on the north side, which in France puts the stops across the street from the square.

Many readers pointed to Berlin's Alexanderplatz, a vast and intense area that includes Berlin's iconic tower, the Fernsehturm.  Alexanderplatz is technically the northeast part of this image, but it's all intimately connected.

Alexplatz

The interaction here is between rapid transit ("U") at the center of the image and tram and bus lines.  One of the tram lines extends northeast and northwest from just south of the rapid transit station.  As I recall some of these trams turn to stop alongside the station (so are not activating the plaza) but others do not, so some people do walk across parts of the plaza.  Also relevant are buses on both the far northeast corner of the image and on Spandauerstrasse, which is the street cutting across the southwest corner.  Greater Alexanderplatz is a series of spaces where the interaction of transit and urban life is quite intricate.

A clearer big-city example is Syntagma Square, Athens.  It's about 110m on a side, and seems to work well, though Google is a little fuzzy there:

Syntagma

Syntagma has an underground metro station on the east side of the image, including entrances right into the square.  Buses are organized as a couplet, and in this case, it appears to be an inverted couplet so that the buses open into the square, but I can't quite be sure.  The Athens Tram also terminates there.  The position next to the Greek parliament building ensures that the square is a symbolic center of the city and nation.

Several readers suggested Piccadilly Gardens, Manchester, UK.  I had in mind hardscaped plazas, but this one is interesting as an example of how much transit work a grassy park with a fountain can do.  It's about 120m x 90m at its widest points.

Piccadilly gardens manchester"

This is clearly a major tram+bus terminal, with lots of space taken up by end-of-line storage as opposed to just stops.  That's part of why the transit operations seem to dominate the space to a degree that urbanists are likely to find objectionable.  Note that the main pedestrian links between connecting services are paved paths across the gardens.  The landscaping is a nice way of saying "this is a park, not just a transit interchange," even as the paths serve the interchange volume.

Last among big-city examples, I'm intrigued by Insurgentes station plaza in Mexico City, which is in a roundabout roughly 120m in diameter. 

Plaza insurgentes mex

Note that the red buses appear to cycle the circle in a contraflow lane, i.e. clockwise where all other traffic is counter-clockwise, so that they open onto the central plaza.  (UPDATEI am now advised that they are operating with-flow, counter-clockwise, but in their own lanes, and have doors on the left that enable them to open onto the plaza.  The two silver-roofed structures are their main stops).  Obviously, this is a massive bus-rail connection point.  The red buses are from the city's Bus Rapid Transit system.  This is certainly enough pedestrian volume to activate a space, and indeed it looks as though some kind of merchant activity is going on.  But of course a roundabout is inevitably more of an island than a heart, as you'll need to go underground, through the subway station, to cross safely to any part of the surrounding district.

But when we step down to smaller cities, or to outer locations that aren't major transit hubs, the successful squares are quite a bit smaller.  Several readers praised Mont Royal station plaza in Montréal.  The subway station is on the west side, with bus stops on the east and north sides.  This looks like a case where terminating buses are actually looping around the square. 

  Mont royal, montreal

But it's only about 50m wide.  Many readers suggested connection-activated squares on this scale, often in secondary nodes of big cities or in suburban areas, especially in Europe.  Many such squares were mentioned, but Stockholm's Odenplen is typical.  And even in North America, small open spaces, usually  less than 50m on a side, are common at some subway stations; Vermont/Santa Monica station in Los Angeles and the two Mission BART stations in San Francisco come to mind.  Another example, at a simiar edge-of-downtown scale, is the PSU Urban Center plaza in Portland, which handles interactions between an inverted couplet of north-south buses and an east-west streetcar.  The open space there, too, is less than 50m on a side.

So to sum up:

  • An obvious larger design point is that civic squares have to be scaled to their catchment area.  The bigger the city and the more central their role in it, the bigger they can be.  For squares that aim to serve a smaller suburban or neighborhood node, the squares are smaller, usually less than 50m on a side.  The plaza we sketched for Surrey (at the beginning of this entry) was probably too big.  Place Bellecour in Lyon a totally open space of 200x100m with only a statue as furniture, probably is too big.
  • At all scales, these squares can work as multiple-purpose plazas while also serving transit connections, and there seem to be many examples of these two functions supporting each other.
  • Inverted couplets are rare but work well with public squares.  The inverted couplet is a key unappreciated feature of the Portland transit mall. 

Thanks to everyone for contributing to this adventure!  I'm sure there are many other great examples I haven't mentioned. 

This work is important to me because many designs for great highrise urban nodes at rail stations collide with the needs of connecting and terminating buses, and it's often tempting to push the buses away.  These examples, at a range of scales, capture how transit connections and urban life can happen in the same place, and indeed support each other.  Links to other great examples are welcome!