How many trips generated by high density residential?

[pdxTom]

Hi,

I am concerned that a proposed development is using too low a trip generation figure. The project is a high density condo project in steep hills near downtown.

While the project connects to a street with bus service every 15 minutes, the steep terrain, limited visibility curves in the transit street (no stops or other buildings currently in the area), and lack of sidewalks makes me think that transit use will be lower than typical. Based upon the preliminary plans, the walk to the closest safe location for a transit stop is about 800 feet from the closest building and 1150 feet to the furthest, with an elevation change about 100 feet.

All dimensions are scaled from a dwg on normal letter sized paper.

The project has 279 units and 283 parking spaces. While one space per unit is common in relatively similar projects around here, all those projects have good sidewalks, some shopping within easy walking/biking distance, and are closer to transit stops. Except for a half dozen spaces that are time limited for a park (and are supposed to be for park use only), there is no on street parking or other public parking within a quarter mile or more walk.

The steep hills resulted in narrow streets without sidewalks when the streets were built 50-100 years ago.

My questions are below. I may need to convince others that this project’s assumptions are wrong or unrealistic. Please cite sources whenever possible, although I welcome your unsourced replies as well.

1) Given the poor non-auto access outlined above, does the project need more guest parking spaces?

2) The access street for the project has congestion issues, and the project may be scaled back due to other zoning issues. How many new motor vehicle trips per unit or parking space would you expect or use for design and approval purposes?

Tom

[JusticeZero]

Frankly, it probably has far too many parking spaces. There's been a number of developments in various parts of the city here where they do things like put in a residential high density with zero parking, and part of your conditions of residency is to waive your eligibility for a parking pass nearby. People still seem to snap them up, and they fit a lot of units in where they would have needed to put parking otherwise.
Perhaps residents can sell back their parking allotments as guest parking? Perhaps the transit operators can be convinced to put a stop at the entrance? Can the plan be adjusted to make it easier to serve by transit? Why can't sidewalks be added?
I will openly note that i'm pretty anti-parking, ever since I realized just how much that stuff cost.. parking lots, and anything that needs to have a car on it, eat raw land like a fat uncle nobody recognizes at thanksgiving dinner.

[DetroitPlanner]

Trips won't tell you squat about number of spaces needed for residential. Most high income people have cars. As income decreases the likelyhood of whether or not they have a car decreases. This does not translate into trips, as someone with a car may not use it everyday if they live in an area with good transit/sidewalks.

Keep in mind that trip generation is just one step. You then have to access trip mode, which may be SOV, transit, ped, or bike.

If you are trying to build a high income condo project, you may have a hard time selling the units if you do not have easily accessible parking. You would have an easier time selling condos to lower income people with fewer cars. This will impact the revenue generated by your project.

[JusticeZero]

Most high income people have cars. As income decreases the likelyhood of whether or not they have a car decreases.

Are you sure on that? Because it's the opposite of what i've seen from studies and demographics recently. I think it might be a city by city trend, rather than a "general rule"; certainly the demographics i've been seeing indicates that bike commuting is positively correlated with income and education level, and indicators of lower socioeconomic class correlate positively with distance from the CBD, along with auto ownership rates.

[DetroitPlanner]

Are you sure on that? Because it's the opposite of what i've seen from studies and demographics recently. I think it might be a city by city trend, rather than a "general rule"; certainly the demographics i've been seeing indicates that bike commuting is positively correlated with income and education level, and indicators of lower socioeconomic class correlate positively with distance from the CBD, along with auto ownership rates.

I am talking simple economics.

Higher income people can afford cars more easily than lower income people.
The more disposable income someone has the more likely they are to do things that will help them make their life easier. Having a car at your disposal makes your life easier.
Just because a person with high income would choose to take a bike under certain conditions for commute does not tell you if that person is also a car owner or not.

For example, I've been known to take the bus to work, but that does not mean I don't have a car. I also have a bike and have used that for trips to the local stores or restraunts, yet I still own a car.

Mode is an independant variable to the trip.
Automobile is dependant upon ability to afford it.
You don't need to be rich to own a bike. I've never had a bike that cost me more than $20,
Bikes are affordable tranportation and are used by all sectors of the population.
Car ownership is a symbol of status and wealth.
Its true that in general higher income people are more healthy and apt to ride a bike because they see exercise as a benefit, but this is irrelevant to owning a car or not.
Most people who own cars want a place to store them close to their origin and destination points.

[JusticeZero]

Higher income people can afford cars more easily than lower income people.

Right, but the fact of the matter is that "owning a car" has trickled down to the point where only those few outliers who fall off the bottom of the ladder are unable to acquire a car if they so chose. Whether they SHOULD own a car is a different question entirely. Some of the most dirt-poor people I have seen own cars - plural. I have met homeless people who own automobiles. But I honestly can't think of that many times that i've seen people who lack college educations riding a bike anywhere.
It's true that 'car ownership is a status symbol' but honestly, it doesn't seem to symbolize much anymore, and I suspect it's shifted from "status of wealth" to "rite of passage" status.

[Cardinal]

The car ownership rate is not even worth discussing. Anyone who can afford to buy a condo can afford to own a car. The reality is that any middle- or higher-income household is likely to have more than one car. Limited parking is going to make it more difficult to sell these units, as many of the potential buyers will be looking for a place to park. Given all of the conditions you have described, the distance to transit and the lack of on-street parking, there is likely going to be a problem in the future as residents complain of being unable to park near their building.

Portland and other cities have made a concerted effort to force residents to abandon their preferences for vehicles and travel modes. Taken all together, their techniques have succeeded in making cities which are unfriendly to cars. Some people have embraced the results and some are grudgingly changing their ways to accommodate them. The majority of people are still not changing, nor will they.

[digger]

As my post count will show, I'm very new to the forum. And as my name suggests, I'm not a planner; I'm an excavating contractor who found this site to have some interesting reading. With that understood, please forgive me if the following question/comment is naive or inappropriate. I'll try to relate it to the question posed in the opening post.

Is the purpose of planning to get people to behave in the way that the planners wish them to, or is the purpose of planning to come up with solutions that will deal optimally with people behaving the way they wish to?

Specific to this discussion, planning something with no/few parking spaces seems an attept at the former. "If they can't park, they'll abandon the notion that car ownership is a necessity." Planning something with parking spaces adequate to the known reliance on personally owned motor vehicles (I know there are exceptions, but in my experience most people, in most places, want to have a car at their disposal, even if there are alternatives available), seems to me to be an example of the latter.

Which is your goal, and which has a greater chance of proving successful?

[DetroitPlanner]

Sometimes I am amazed by the number of people who take positions that a planner's job is to fundementally change peoples behaviours. Behaviour is changed through the introduction of technology and economices. It is the repsonisbility of the planner to listen to the needs of its residents and provide an adequete infrastructure.

Again, I restate my original contention that the number of trips canot be reflected in the number of parking spaces needed, as most folks who own condos are rich enough to also own cars; but not all trips are taken by that mode.

Trip generation is only the first step of the transportation modeling process. Next comes modal assignment, then route assignment. It is also possible to have 12 units with space to park 12 cars, but only have 2 residents own cars. Would you still model your trips based upon cars? Cars are just one of several modal options for trips.

If people expect places to store cars, and you don't design that into the project, you will have problems selling your units and turning a profit. You don't want to plan something that will fail based upon being a liberal do gooder. Cars are part of the modern world either design to accomodate them or expect the project to fail. You cannot apply tip generation to number of spaces at a house the same way you can for a business. A home operates primarilly as an origin, and an office or store is a destination.

You should design your condo parking to match what is expected by your local zoning ordinances.

[JusticeZero]

Well, frankly, one of the main issues faced is that people still mistakenly think of transit as serving a captive market. That "captive market" now has cars. Instead, transit needs to be made competitive with the auto, which by all rights it should be save for the fact that massive amounts of money is wasted on -requiring- oceans of car parking on premium land, and people see no problem with putting in special dispensation in places where different modes of transportation mix for the minority users (cars) in preference over the majority users (walking, transit, etc.) as measured by how many people are actually being served by that mode in the conflict point when the conflict arises. Is it really reasonable for four people to delay the trip of fourty people?
You can't both incentivize transit AND car use at the same time, the costs go through the roof and you end up trying to pave everything over. Adding highway capacity has been tried, and it FAILS. The balancing factor for car use seems to be traffic inconvenience, as opposed to other factors; clear up traffic, people drive more and the new road is filled to capacity. Cars are given massive incentives for use, and transit typically is treated as garbage for the 'poor filthy people'. We will never get a good system if it is viewed as belonging to the underclass - and the underclass are in cars now anyways.
We're not going to be able to continue to serve massive numbers of cars in this way. There will always be more outcry for more roads, and so on, and meanwhile, we have an aging population who soon will start being unable to drive everywhere who will be stranded. We also have all the issues with kids who are getting fat because they have to be driven three blocks because the road with the speeding cars on it is so scary. And then you have the spectre of peak oil and such to worry about.
I've talked to a lot of people who use transit. They state, essentially, that they once for some reason had to take the bus and such, and by the time their other choices openned up, they had learned the system well enough that they no longer felt that they "needed" a car. Mind you, for that to work you need a system that isn't abysmal; enough cities have experimented with ways to get their transit system effective that there is little excuse to not be able to do at least some of the things that work.

Car improvements have been tried. A lot. They don't work. They drain money from people, isolate those who cannot drive, and choke the roads. And soon, we're going to have a lot of elders who are trapped in their houses because they can't get anywhere.
Even the old canards in favor of the pessimistic road priority are fading. The old saying about a certain density being required for transit (originally from the Chicago study) has been torn apart; there were other interpretations that were a better fit to the data.
So yes, I want to get people out of cars because cars haven't worked for us, and I want things that work.

[DetroitPlanner]

But I honestly can't think of that many times that i've seen people who lack college educations riding a bike anywhere.

If you go to Chicago, Illinois, I will have my 5 year old niece ride her bike for you. She can't spell yet, but she knows how to ride a bike. You must have a really biased sample. There are plenty of places in the world with low college degree attainment rates where people ride bikes everywhere. Have you been to Ireland, India, or China? Have you been into inner-cities of the United States? It don't take a college degree to figure out that a bike is a good cheap form of transportation.

[digger]

Sometimes I am amazed by the number of people who take positions that a planner's job is to fundementally change peoples behaviours. Behaviour is changed through the introduction of technology and economices. It is the repsonisbility of the planner to listen to the needs of its residents and provide an adequete infrastructure.

That's why I asked the question. Reading your comments, and those of JusticeZero, I see both sides of that question at work. I wondered if someone would say whether the planner's role is expressly to do one or the other, rather than me haviing to draw implications.

The balancing factor for car use seems to be traffic inconvenience, as opposed to other factors; clear up traffic, people drive more and the new road is filled to capacity.

Car improvements have been tried. A lot. They don't work. They drain money from people, isolate those who cannot drive, and choke the roads.

I'm sorry, but that stikes me as being every bit as logical as the quote attributed to baseball manager Yogi Berra: "Nobody ever goes to that resturaunt, because it's always too crowded." People are voting with their dollars and their driving habits in favor of the automobile. Cars apparently work for a lot of people despite their drawbacks. How to deal with the fallout from that is a different question.

Am I being unfair in thinking you see your goal in planning as being an agent of behavioral change, rather than as developing solutions that are optimal to the behaviors people prefer?

[Cardinal]

That's why I asked the question. Reading your comments, and those of JusticeZero, I see both sides of that question at work. I wondered if someone would say whether the planner's role is expressly to do one or the other, rather than me haviing to draw implications.

It has been my experience that there are certainly planners out there who have a conception of what the "perfect" world is, and then try to force people to go along with their view. In a markeplace which really does (despite all that we are told) offer choice, people do continue to opt for detached homes on large lots. No not everyone, but still a plurality. This irks some people who would prefer to see us all living in dense, mixed-use neighborhoods, whether we like it or not.

I believe it is the planner's role to educate the public about all of their options, then provide the tools to achieve the kind of places that the public desires, even when it does not match what we would ourselves desire, or what some "planning guru" dictates as the perfect form of development.

[JusticeZero]

People seem to actually like public transit, it's just that they often don't have any that they view as viable. And people who work in governance tend to grossly underestimate that desire.
People I know don't drive a car because they like to drive a car, they drive a car because they don't have a real alternative. Cars are stressful, expensive, and dangerous. Buses run once an hour and finish at 10:30, so if you want to leave after 9:00 you're probably not going to have that option. The transfer points needed to make a full journey are inconvenient and uncoordinated. Of course there's no expansion, because they can't really measure demand for services they don't have.

Personally, my present thing is that i'm worried about the elderly who are going to lose automobility in a few years. When my mother's eyesight starts to go, she deserves to be able to get to the store, her favorite shops, and to visit with people without having to preplan days in advance. If something happens and she can't drive a car, she'll have to take transit. Right now the transit system is simply not up to the challenge, in great part because people keep thinking of it as the "loser cruiser" rather than as something that is meant to compete with as a viable alternative to a car.

[DetroitPlanner]

People seem to actually like public transit, it's just that they often don't have any that they view as viable. And people who work in governance tend to grossly underestimate that desire.

Personally, my present thing is that i'm worried about the elderly who are going to lose automobility in a few years. When my mother's eyesight starts to go, she deserves to be able to get to the store, her favorite shops, and to visit with people without having to preplan days in advance.

First paragraph reminds me of an Onion survey that revealed 95 percent of everyone agrees that they want trainsit for everyone else so they can drive faster!

Elderly Mobility is currently a hot topic in transporfation planning. I'm sure that Australia is dealing with the same post war baby boom that the States are. I know we are trying to educate people on it at my agency (we do demographic forecasting and transportation planning primarilly), the problem is, everyone is so results now driven that they can't see the big picture. Its going to have to become a huge problem before it is addressed.

[JusticeZero]

Well, if you increase the availability and functioning of transit, without modifying cars, it will be an incentive for people to drive, yes. That means that you're channeling effort into the transportation system, and your result is that people make more trips period. By lowering the "cost" of travel, you pull the marginal utility, and now people jump in their car or a bus to go to the store on the other side of town for a pack of gum. The net result is that you're really not helping anything.

Other things have been looked at; for instance, economists like road pricing, but that seems to be a failure - or rather, it works toward ends that nobody actually wants. In Singapore, road pricing allows the lucky few car owners to drive around unimpeded, managing to rack up absolutely mind-boggling miles per auto per year.

Just because a trend exists does not mean that that is what is desired. The forces that create roads, transit, etc. are not done by educated democratic processes, they are in a way 'inflicted' on the ground from 'on high' modelling and projections of trends based on assumptions that the previous series of likewise dictated developments were what were wanted by the people. If we're inflicting freeways on places, it's not so hard to imagine that we can inflict improved public transit networks.
People have a stated preference for improved public transit over roads. Policymakers often have a stated preference for public transit too, but assume that the populace wants roads.
The end decision seems to often end up being made by Marty the Road Engineer in sub-basement two, who spends his days finetuning a mathematical model of the city based on assumptions that people park their cars in their offices and would rather tapdance naked in Siberia in front of their grandmother than transfer from one bus to another, no matter how painless the transfer might be. Marty has no public accountability, and no public input. Why Marty would be considered the guru of where people want a road is a mystery.

[jmello]

Right, but the fact of the matter is that "owning a car" has trickled down to the point where only those few outliers who fall off the bottom of the ladder are unable to acquire a car if they so chose. Whether they SHOULD own a car is a different question entirely. Some of the most dirt-poor people I have seen own cars - plural. I have met homeless people who own automobiles.

We have two Census tracts in our city where more than 39.0% of households do NOT own a vehicle. We have several others where that number is greater than 20.0%. This is likely not by choice, as it correlates directly with the median income of the tracts.

But I honestly can't think of that many times that i've seen people who lack college educations riding a bike anywhere.
It's true that 'car ownership is a status symbol' but honestly, it doesn't seem to symbolize much anymore, and I suspect it's shifted from "status of wealth" to "rite of passage" status.

Again, I would disagree. The VAST majority of people on bicycles here are poor and working class. They are often wearing fast food uniforms or dirty ripped clothing. Portland is likely much different, but much of that has to do with urban wealth not necessarily culture.

Back to the topic: If there are not enough parking spaces, then people who want to have more than one car will not buy a unit. Plain and simple. You already said that there is no public parking anywhere nearby. Why is this the government or neighbors' concern?

[jordanb]

People here who are arguing about if a planner should or shouldn't try to change the world to fit anything are ignoring the fact that the issue here is that the developer wants to build a building with 185 parking spaces. and thinks he can make a profit from it, and the OP wants to use the powers of the city to force him to increase the parking.

Come on people, this is not a developer trying to low-ball a low-income development to jeprodize the health or safety of residents who have little choice in where to live. This is a developer building and marketing a condo development to presumably sophisticated wealthy buyers and has determined that that market will support his decision to put 185 spaces in the building.

And I don't think it's the job of a planner to anticipate future trends in housing (such to claim that it will be harder in the future to sell the units as Cardinal has done). Especially if he's going to then reject or demand alterations to a development based upon his predictions.

[Jeff]

Is the purpose of planning to get people to behave in the way that the planners wish them to,

No. But you'd be hard pressed to prove otherwise.

or is the purpose of planning to come up with solutions that will deal optimally with people behaving the way they wish to?

Yes. But you'd be hard pressed to prove it.

[michaelskis]

I agree with Jordan and Card...

However, does each unit have one dedicated parking place? More so, are these all one or two bedroom units? What is the intended demographic to occupy the units? What is the characteristic of the city? What are the standards for other condo projects?

I have seen projects what have required a range from one parking place per unit and one per bed-room. However in some places, parking is a luxury. It is all based on what the market requires.

The building that I bought a condo in has 100 units and 75 parking places. Half of those are car ports that are a monthly rental and the rest is open parking. We do have bus service and on street parking, but being located within a historic district, parking is a premium.

Parking/driving is a privilege... not a right.

[cololi]

Based on the info provided, I don't think they are underparked. I would require better sidewalks (where this project abuts a public street) if they aren't up to current standards and emphasize connectivity to transit, including benches and shelters. 800 feet is not that far and can be covered in 5 minutes or less.

I lived in a development with one stall per unit which had a similar on street parking situation. I ended uo ditching my car after about 2 months and rode my bike, walked, or took the bus when I needed to.

A development with limited parking and served by transit does foster increased ridership on that route. The end result is a development that could possibly increase transit ridership, which seems to be one of the goals of most planners. Call it imposing the planners will, but in this case, the developer is on board as well.

[pdxTom]

Everyone,

Thanks for your responses so far.

I would like to get this thread back on track with my original questions, plus one new question. Please specifically to the questions at the bottom of my post and save your philosophical discussions for another thread. I am trying to answer two narrow questions to figure out if they are worth raising to the developer or at public hearings. Please cite sources when possible.

I amazed at how many responses in just one weekend away. I know my response is long, (I was not expecting so many responses in a weekend) so please read carefully to make sure I have not addressed your concern or request for more information!

The questions are at the bottom of this post.

In response to your comments:

--Given the significant differences in auto usage between the United States and other counties, please restrict you comments to the realities of the United States keeping in mind that Portland is not an extremely dense city like New York or Chicago.

--I strongly suspect, based on neighborhood demographics, a high development cost site (building is on top of parking structure, large retaining walls, unstable slopes), and other factors, that the target market will be upper middle class or higher. I do not know how many bedrooms.

-- All of the information I have comes from a four page pre-application conference submittal, most of which is drawings, plus a bit about the developer from other sources.

--Most of the obvious solutions are difficult and expensive due to the steep hills (40-100% slopes).

--I am concerned that the project is poorly designed and will be a major negative on the neighborhood, result in a park being unusable because condo guests are using all the parking meant for park users, and could impact access to a hospital.

--The project’s two lane access road is the primary access road for a large hospital that is one of two trauma centers in the area, so congestion is much more significant than normal. (About a hundred years ago, someone donated land for a medical school, and as a result, we have a large hospital complex located on top of a hill with poor access.).

--I am concerned the guests will use all the half dozen spaces in my favorite park (right next to the proposed entrance), which seems to be the only place they can park.

--I know a few things about the developer. He made his money as a business owner and has no experience as a developer. He is the landowner, and takes the lowest cost way to a greater degree than most. His architects do not have any similar projects with major access issues one their website.

--Many similar projects have a significant number of occupants who like living in the city but commute, usually by car, to jobs in the suburbs.

--Most similar projects in the area have assigned parking that comes with the unit, meaning the spaces are not available to guests.

--I checked the zoning code, and the developer could double the number of parking spaces if he desired.

--The bus line near this project runs from 5:30 am to after midnight, 15 min wait 6am to 7 pm, and 30 min service other times, 7 days a week.

--For readers outside the United Sates, remember than Americans, even in Portland, are more car loving than the rest of the world. And while I think America would be better off if we reduced auto use, I am dealing with reality.

--One building is 1150 feet away (800 is the closest building), and part of the walkway appears to have 15-20% grade for 200 feet, which is steep for some people.

---------

Due to the steep hills, and sharp corners, the distances I provided are to the closest feasible location for a bus stop under the current proposal. The buildings are a hundred vertical feet (30 meters) above the access road with a long driveway. Adding a bus stop is no problem as long as the stop is safe for pedestrians and drivers, the problem is steep difficult land.

Adding a staircase to the project might allow a closer stop, although the sight distances would only be about 100-125 feet (30-40m) and massive, expensive retaining needed to create even a 5-6 ft (1.75-2m) wide sidewalk for riders to stand on, assuming the hospital did not demand even more expensive full pullouts.
--------------

My conclusions so far:

--The developer has not proposed installing sidewalks, but the consensus is that he should be required to, which agrees with my own assessment.

--There is no consensus on the quantity of parking needed to ensure guests do not take over the small lot dozen space lot for a nearby park.

Please specifically to the questions below and save your philosophical discussions for another thread. I am trying to answer two narrow questions to figure out if they are worth raising to the developer or at public hearings. Please cite sources when possible.

My questions are:

1) For a high density residential project, what is the expected trip generation per unit, both under the current proposal which does not have sidewalks and if the proposal was modified to add sidewalks?

2) Since many projects are sold on the basis of one reserved space per unit, is the lack of on site parking or street parking for guests a problem?

3) If the project is built as proposed, how does one keep condo guests from filling up the small lot for park use while keeping the lot available for park users?

[DetroitPlanner]

My questions are:

1) For a high density residential project, what is the expected trip generation per unit, both under the current proposal which does not have sidewalks and if the proposal was modified to add sidewalks?

2) Since many projects are sold on the basis of one reserved space per unit, is the lack of on site parking or street parking for guests a problem?

3) If the project is built as proposed, how does one keep condo guests from filling up the small lot for park use while keeping the lot available for park users?

1). Your MPO (Metropolitan Planning Organization) should be able to tell you a percentage of trips by mode. Typically a household generates 12 trip ends per day. For condos I would go with a lower number of maybe six to eight depending on number of rooms.

2). If there is parking across the street at the park, or if street parking is available, it should not be a very big issue.

3). You could suggest that the parks department look into it, and tell them there is a liability issue for them and that they should sign the lot and enforce it against overnight parking.

[JusticeZero]

Adding a staircase to the project might allow a closer stop, although the sight distances would only be about 100-125 feet (30-40m) and massive, expensive retaining needed to create even a 5-6 ft (1.75-2m) wide sidewalk for riders to stand on, assuming the hospital did not demand even more expensive full pullouts.

That may be more affordable than adding parking, depending on local land value. Land value tends to be high in Portland, as I recall.

[Cardinal]

People here who are arguing about if a planner should or shouldn't try to change the world to fit anything are ignoring the fact that the issue here is that the developer wants to build a building with 185 parking spaces. and thinks he can make a profit from it, and the OP wants to use the powers of the city to force him to increase the parking.

Come on people, this is not a developer trying to low-ball a low-income development to jeprodize the health or safety of residents who have little choice in where to live. This is a developer building and marketing a condo development to presumably sophisticated wealthy buyers and has determined that that market will support his decision to put 185 spaces in the building.

And I don't think it's the job of a planner to anticipate future trends in housing (such to claim that it will be harder in the future to sell the units as Cardinal has done). Especially if he's going to then reject or demand alterations to a development based upon his predictions.

My point was not that the units would not sell, but that the lack of ample parking is going to result in a more limited pool of buyers. My concern with the development would be if it is likely to create a problem for the city in the future. In this case, it may be that the lack of parking in the development would create a need for more on-street parking, which may not be possible in this location.

I have recommended approval of developments with fewer parking stalls than those required by code. I have also recommended denial of projects with fewer parking spaces than code requires. It is something to be considered on a case-by-case basis. Face it, as planners we always make choices based on our predictions of what may happen. What is important is that we do so in a way that attempts to eliminate bias, especially our own.