2020-08-11 00:57:11 +03:00
<!DOCTYPE HTML>
< html lang = "en" class = "sidebar-visible no-js light" >
< head >
<!-- Book generated using mdBook -->
< meta charset = "UTF-8" >
< title > How it works - A/B Street< / title >
< meta content = "text/html; charset=utf-8" http-equiv = "Content-Type" >
< meta name = "description" content = "" >
< meta name = "viewport" content = "width=device-width, initial-scale=1" >
< meta name = "theme-color" content = "#ffffff" / >
< link rel = "shortcut icon" href = "favicon.png" >
< link rel = "stylesheet" href = "css/variables.css" >
< link rel = "stylesheet" href = "css/general.css" >
< link rel = "stylesheet" href = "css/chrome.css" >
< link rel = "stylesheet" href = "css/print.css" media = "print" >
<!-- Fonts -->
< link rel = "stylesheet" href = "FontAwesome/css/font-awesome.css" >
< link href = "https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800" rel = "stylesheet" type = "text/css" >
< link href = "https://fonts.googleapis.com/css?family=Source+Code+Pro:500" rel = "stylesheet" type = "text/css" >
<!-- Highlight.js Stylesheets -->
< link rel = "stylesheet" href = "highlight.css" >
< link rel = "stylesheet" href = "tomorrow-night.css" >
< link rel = "stylesheet" href = "ayu-highlight.css" >
<!-- Custom theme stylesheets -->
< / head >
< body >
<!-- Provide site root to javascript -->
< script type = "text/javascript" >
var path_to_root = "";
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "light" : "light";
< / script >
<!-- Work around some values being stored in localStorage wrapped in quotes -->
< script type = "text/javascript" >
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') & & theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') & & sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
< / script >
<!-- Set the theme before any content is loaded, prevents flash -->
< script type = "text/javascript" >
var theme;
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = default_theme; }
var html = document.querySelector('html');
html.classList.remove('no-js')
html.classList.remove('light')
html.classList.add(theme);
html.classList.add('js');
< / script >
<!-- Hide / unhide sidebar before it is displayed -->
< script type = "text/javascript" >
var html = document.querySelector('html');
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
html.classList.remove('sidebar-visible');
html.classList.add("sidebar-" + sidebar);
< / script >
< nav id = "sidebar" class = "sidebar" aria-label = "Table of contents" >
< div class = "sidebar-scrollbox" >
2020-11-09 22:42:58 +03:00
< ol class = "chapter" > < li class = "chapter-item expanded " > < a href = "index.html" > < strong aria-hidden = "true" > 1.< / strong > Overview< / a > < / li > < li class = "chapter-item expanded " > < a href = "howto/index.html" > < strong aria-hidden = "true" > 2.< / strong > Instructions< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "howto/map_parking.html" > < strong aria-hidden = "true" > 2.1.< / strong > How to map on-street parking< / a > < / li > < li class = "chapter-item expanded " > < a href = "howto/new_city.html" > < strong aria-hidden = "true" > 2.2.< / strong > Importing a new city< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "how_it_works.html" class = "active" > < strong aria-hidden = "true" > 3.< / strong > How it works< / a > < / li > < li class = "chapter-item expanded " > < a href = "case_studies/index.html" > < strong aria-hidden = "true" > 4.< / strong > Case studies< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "case_studies/lake_wash.html" > < strong aria-hidden = "true" > 4.1.< / strong > Lake Washington Blvd Stay Healthy Street< / a > < / li > < li class = "chapter-item expanded " > < a href = "case_studies/west_seattle.html" > < strong aria-hidden = "true" > 4.2.< / strong > West Seattle mitigations< / a > < / li > < li class = "spacer" > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "dev/index.html" > < strong aria-hidden = "true" > 5.< / strong > Developer guide< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "dev/misc_tricks.html" > < strong aria-hidden = "true" > 5.1.< / strong > Misc developer tricks< / a > < / li > < li class = "chapter-item expanded " > < a href = "dev/api.html" > < strong aria-hidden = "true" > 5.2.< / strong > API< / a > < / li > < li class = "chapter-item expanded " > < a href = "dev/testing.html" > < strong aria-hidden = "true" > 5.3.< / strong > Testing< / a > < / li > < li class = "chapter-item expanded " > < a href = "dev/mass_import.html" > < strong aria-hidden = "true" > 5.4.< / strong > Importing many maps< / a > < / li > < li class = "chapter-item expanded " > < a href = "dev/data.html" > < strong aria-hidden = "true" > 5.5.< / strong > Data organization< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "map/index.html" > < strong aria-hidden = "true" > 6.< / strong > Map model< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "map/details.html" > < strong aria-hidden = "true" > 6.1.< / strong > Details< / a > < / li > < li class = "chapter-item expanded " > < a href = "map/importing/index.html" > < strong aria-hidden = "true" > 6.2.< / strong > Importing< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "map/importing/convert_osm.html" > < strong aria-hidden = "true" > 6.2.1.< / strong > convert_osm< / a > < / li > < li class = "chapter-item expanded " > < a href = "map/importing/geometry.html" > < strong aria-hidden = "true" > 6.2.2.< / strong > Road/intersection geometry< / a > < / li > < li class = "chapter-item expanded " > < a href = "map/importing/rest.html" > < strong aria-hidden = "true" > 6.2.3.< / strong > The rest< / a > < / li > < li class = "chapter-item expanded " > < a href = "map/importing/misc.html" > < strong aria-hidden = "true" > 6.2.4.< / strong > Misc< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "map/edits.html" > < strong aria-hidden = "true" > 6.3.< / strong > Live edits< / a > < / li > < li class = "chapter-item expanded " > < a href = "map/platform.html" > < strong aria-hidden = "true" > 6.4.< / strong > Exporting< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "trafficsim/index.html" > < strong aria-hidden = "true" > 7.< / strong > Traffic simulation< / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "trafficsim/discrete_event.html" > < strong aria-hidden = "true" > 7.1.< / strong > Discrete event simulation< / a > < / li > < li class = "chapter-item expanded " > < a href = "trafficsim/travel_demand.html" > < strong aria-hidden = "true" > 7.2.< / strong > Travel demand< / a > < / li > < li class = "chapter-item expanded " > < a href = "trafficsim/gridlock.html" > < strong aria-hidden = "true" > 7.3.< / strong > Gridlock< / a > < / li > < li class = "chapter-item expanded " > < a href = "trafficsim/trips.html" > < strong aria-hidden = "true" > 7.4.< / strong > Multi-modal trips< / a > < / li > < li class = "chapter-item expanded " > < a href = "trafficsim/live_edits.html" > < strong aria-hidden = "true" > 7.5.< / strong > Live edits< / a > < / li > < li class = "chapter-item expa
2020-08-11 00:57:11 +03:00
< / div >
< div id = "sidebar-resize-handle" class = "sidebar-resize-handle" > < / div >
< / nav >
< div id = "page-wrapper" class = "page-wrapper" >
< div class = "page" >
< div id = "menu-bar-hover-placeholder" > < / div >
< div id = "menu-bar" class = "menu-bar sticky bordered" >
< div class = "left-buttons" >
< button id = "sidebar-toggle" class = "icon-button" type = "button" title = "Toggle Table of Contents" aria-label = "Toggle Table of Contents" aria-controls = "sidebar" >
< i class = "fa fa-bars" > < / i >
< / button >
< button id = "theme-toggle" class = "icon-button" type = "button" title = "Change theme" aria-label = "Change theme" aria-haspopup = "true" aria-expanded = "false" aria-controls = "theme-list" >
< i class = "fa fa-paint-brush" > < / i >
< / button >
< ul id = "theme-list" class = "theme-popup" aria-label = "Themes" role = "menu" >
< li role = "none" > < button role = "menuitem" class = "theme" id = "light" > Light (default)< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "rust" > Rust< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "coal" > Coal< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "navy" > Navy< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "ayu" > Ayu< / button > < / li >
< / ul >
< button id = "search-toggle" class = "icon-button" type = "button" title = "Search. (Shortkey: s)" aria-label = "Toggle Searchbar" aria-expanded = "false" aria-keyshortcuts = "S" aria-controls = "searchbar" >
< i class = "fa fa-search" > < / i >
< / button >
< / div >
< h1 class = "menu-title" > A/B Street< / h1 >
< div class = "right-buttons" >
< a href = "print.html" title = "Print this book" aria-label = "Print this book" >
< i id = "print-button" class = "fa fa-print" > < / i >
< / a >
< / div >
< / div >
< div id = "search-wrapper" class = "hidden" >
< form id = "searchbar-outer" class = "searchbar-outer" >
< input type = "search" name = "search" id = "searchbar" name = "searchbar" placeholder = "Search this book ..." aria-controls = "searchresults-outer" aria-describedby = "searchresults-header" >
< / form >
< div id = "searchresults-outer" class = "searchresults-outer hidden" >
< div id = "searchresults-header" class = "searchresults-header" > < / div >
< ul id = "searchresults" >
< / ul >
< / div >
< / div >
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
< script type = "text/javascript" >
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
< / script >
< div id = "content" class = "content" >
< main >
< h1 > < a class = "header" href = "#how-ab-street-works" id = "how-ab-street-works" > How A/B Street works< / a > < / h1 >
< p > The overview:< / p >
< ol >
< li > A detailed map of Seattle is built from
< a href = "https://www.openstreetmap.org/about" > OpenStreetMap (OSM)< / a > < / li >
< li > A realistic set of daily trips by car, bike, foot, and bus are simulated< / li >
< li > You make small changes to roads and intersections< / li >
< li > You explore how these changes affect the trips< / li >
< / ol >
< p > Details below. Many limitations are mentioned; improvements are ongoing. I'll
add pictures to explain better when I get time.< / p >
<!-- ts -->
< ul >
< li > < a href = "#how-ab-street-works" > How A/B Street works< / a >
< ul >
< li > < a href = "#driving" > Driving< / a > < / li >
< li > < a href = "#parking" > Parking< / a > < / li >
< li > < a href = "#biking" > Biking< / a > < / li >
< li > < a href = "#walking" > Walking< / a > < / li >
< li > < a href = "#transit" > Transit< / a > < / li >
< li > < a href = "#intersections" > Intersections< / a > < / li >
< li > < a href = "#people-and-trips" > People and trips< / a > < / li >
< li > < a href = "#map-edits" > Map edits< / a > < / li >
< / ul >
< / li >
< / ul >
<!-- Added by: dabreegster, at: Mon Jun 8 12:17:13 PDT 2020 -->
<!-- te -->
< h2 > < a class = "header" href = "#driving" id = "driving" > Driving< / a > < / h2 >
< ul >
< li > Movement: no acceleration, go the full speed limit of the road unless there's
a slower vehicle in front< / li >
< li > Lanes
< ul >
< li > No over-taking or lane-changing in the middle of a road, only at
intersections< / li >
< li > Strange choice of lanes -- the least full at the time of arrival< / li >
< li > Narrow two-way neighborhood roads where, in practice, only one car at a time
can go are currently full two-way roads< / li >
< / ul >
< / li >
< li > Routing is based on fastest time assuming no traffic
< ul >
< li > No rerouting if the driver encounters a traffic jam< / li >
< / ul >
< / li >
< / ul >
< h2 > < a class = "header" href = "#parking" id = "parking" > Parking< / a > < / h2 >
< ul >
< li > Types
< ul >
< li > On-street: parallel parking lanes from
< a href = "http://data-seattlecitygis.opendata.arcgis.com/datasets/blockface" > GeoData blockface dataset< / a >
2020-09-25 05:37:16 +03:00
and < a href = "howto/map_parking.html" > manually mapped< / a > < / li >
2020-08-11 00:57:11 +03:00
< li > Off-street: most buildings have at least a few parking spots in a driveway
or carport
< ul >
< li > Currently experimenting in the downtown map: set the number of available
spots based on number of cars seeded at midnight< / li >
< / ul >
< / li >
< li > Parking lots: the number of spots is inferred< / li >
< / ul >
< / li >
< li > Restrictions
< ul >
< li > All spots are public except for the few spots associated with each building< / li >
< li > No time restrictions or modeling of payment< / li >
< / ul >
< / li >
< li > How cars park
< ul >
< li > Drivers won't look for parking until they first reach their destination
building. Then they'll drive to the nearest open parking spot (magically
knowing what spots are open, even if they're a few blocks away). If somebody
else has taken the spot when they arrive, they'll try again.< / li >
< li > Once a driver finds an open spot, they'll take 10-15 seconds to park. They
block the road behind them in the meantime. There are no conflicts between
pedestrians and cars when using a driveway. Cars won't make left turns into
or out of driveways.< / li >
< / ul >
< / li >
< li > Some parking along the boundary of the map is " blackholed" , meaning it's
impossible to actually reach it. Nobody will use these spots.< / li >
< / ul >
< h2 > < a class = "header" href = "#biking" id = "biking" > Biking< / a > < / h2 >
< ul >
< li > Choice of lane
< ul >
< li > Multi-use trails like the Burke Gilman and separated cycle-tracks like the
one along Broadway are currently missing< / li >
< li > Cyclists won't use an empty parking lane< / li >
< li > On roads without a bike lane, cyclists currently won't stick to the
rightmost lane< / li >
< li > No over-taking yet, so cars can get stuck behind a bike even if there's a
passing lane< / li >
< / ul >
< / li >
< li > Elevation change isn't factored into route choice or speed yet; pretend
everybody has an e-bike< / li >
< li > Beginning or ending a cycling trip takes 30-45 seconds. Locking up at bike
racks with limited capacity isn't modeled; in practice, it's always easy in
Seattle to find a place to lock up.< / li >
< / ul >
< h2 > < a class = "header" href = "#walking" id = "walking" > Walking< / a > < / h2 >
< ul >
< li > Not using sidewalk and crosswalk data from OSM yet< / li >
< li > No jay-walking, even on empty residential streets< / li >
< li > Pedestrians can't use roads without sidewalks at all
< ul >
< li > When a road only has a sidewalk on one side, driveways will cross the road< / li >
< / ul >
< / li >
< li > Pedestrians can " ghost" through each other; crowds of people can grow to any
size< / li >
< / ul >
< h2 > < a class = "header" href = "#transit" id = "transit" > Transit< / a > < / h2 >
< ul >
< li > The modeling of buses is extremely simple and buggy; I'll work on this soon< / li >
< li > No light rail yet< / li >
< / ul >
< h2 > < a class = "header" href = "#intersections" id = "intersections" > Intersections< / a > < / h2 >
< ul >
< li > Conflicting movements are coarse: a second vehicle won't start a conflicting
turn, even if the first vehicle is physically out of the way but still
partially in the intersection< / li >
< li > Most of the time, vehicles won't " block the box" -- if there's no room in the
target lane, a vehicle won't start turning and risk getting stuck in the
intersection< / li >
< li > Traffic signals
< ul >
< li > Only fixed timers; no actuated signals or
< a href = "https://www.seattle.gov/transportation/projects-and-programs/programs/technology-program/mercer-scoot" > centralized control< / a >
yet< / li >
2020-08-29 03:39:14 +03:00
< li > The timing and stages are automatically guessed, except some intersections
2020-08-11 00:57:11 +03:00
are
< a href = "https://docs.google.com/document/d/1Od_7WvBVYsvpY4etRI0sKmYmZnwXMAXcJxVmm8Iwdcg/edit?usp=sharing" > manually mapped< / a > < / li >
< li > No pedestrian beg buttons; walk signals always come on< / li >
< li > The signal doesn't change for rush hour or weekday/weekend traffic; there's
one pattern all day< / li >
< / ul >
< / li >
< li > Turn restrictions from OSM are applied
< ul >
< li > Per lane (left turn only from leftmost lane), entire roads, multiple
intersections< / li >
< / ul >
< / li >
< / ul >
< h2 > < a class = "header" href = "#people-and-trips" id = "people-and-trips" > People and trips< / a > < / h2 >
< ul >
< li > A " synthetic population" of ~700,000 people come from
< a href = "https://www.psrc.org/activity-based-travel-model-soundcast" > PSRC's Soundcast model< / a >
< ul >
< li > Soundcast uses census, land-use, vehicle counts, and commuter surveys. The
current data is from 2014.< / li >
< li > All driving trips are currently single-occupancy; no car-pooling or
ridesharing< / li >
< li > Parked cars are initially placed at midnight based on the number of trips
between buildings< / li >
< / ul >
< / li >
< li > Each person's schedule never changes
< ul >
< li > Your changes to the map won't yet convince somebody to take a bus or walk
instead of drive< / li >
< / ul >
< / li >
< / ul >
< h2 > < a class = "header" href = "#map-edits" id = "map-edits" > Map edits< / a > < / h2 >
< ul >
< li > Types of edits
< ul >
< li > Change types of lanes. Sometimes this is unrealistic based on actual road
width, but data for this is unavailable.< / li >
< li > Reversing direction of lanes< / li >
< li > Changing stop signs< / li >
< li > Changing traffic signal timing< / li >
< li > Closing roads and intersections for construction, forcing rerouting< / li >
< / ul >
< / li >
< li > Disconnecting the map
< ul >
< li > Generally you can't close sidewalks or make changes to make buildings
unreachable< / li >
< li > You shouldn't be able to make bus stops unreachable, but currently this is
buggy< / li >
< / ul >
< / li >
< / ul >
< / main >
< nav class = "nav-wrapper" aria-label = "Page navigation" >
<!-- Mobile navigation buttons -->
2020-08-26 22:53:16 +03:00
< a rel = "prev" href = "howto/new_city.html" class = "mobile-nav-chapters previous" title = "Previous chapter" aria-label = "Previous chapter" aria-keyshortcuts = "Left" >
2020-08-11 00:57:11 +03:00
< i class = "fa fa-angle-left" > < / i >
< / a >
2020-08-26 22:53:16 +03:00
< a rel = "next" href = "case_studies/index.html" class = "mobile-nav-chapters next" title = "Next chapter" aria-label = "Next chapter" aria-keyshortcuts = "Right" >
2020-08-11 00:57:11 +03:00
< i class = "fa fa-angle-right" > < / i >
< / a >
< div style = "clear: both" > < / div >
< / nav >
< / div >
< / div >
< nav class = "nav-wide-wrapper" aria-label = "Page navigation" >
2020-08-26 22:53:16 +03:00
< a rel = "prev" href = "howto/new_city.html" class = "nav-chapters previous" title = "Previous chapter" aria-label = "Previous chapter" aria-keyshortcuts = "Left" >
2020-08-11 00:57:11 +03:00
< i class = "fa fa-angle-left" > < / i >
< / a >
2020-08-26 22:53:16 +03:00
< a rel = "next" href = "case_studies/index.html" class = "nav-chapters next" title = "Next chapter" aria-label = "Next chapter" aria-keyshortcuts = "Right" >
2020-08-11 00:57:11 +03:00
< i class = "fa fa-angle-right" > < / i >
< / a >
< / nav >
< / div >
< script type = "text/javascript" >
window.playpen_copyable = true;
< / script >
< script src = "elasticlunr.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "mark.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "searcher.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "clipboard.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "highlight.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "book.js" type = "text/javascript" charset = "utf-8" > < / script >
<!-- Custom JS scripts -->
< / body >
< / html >
