mirror of
https://github.com/a-b-street/abstreet.git
synced 2024-12-26 07:52:05 +03:00
318 lines
21 KiB
HTML
318 lines
21 KiB
HTML
<!DOCTYPE HTML>
|
|
<html lang="en" class="sidebar-visible no-js light">
|
|
<head>
|
|
<!-- Book generated using mdBook -->
|
|
<meta charset="UTF-8">
|
|
<title>Map model - 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">
|
|
<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"><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></ol></li><li class="chapter-item expanded "><a href="../map/index.html" class="active"><strong aria-hidden="true">6.</strong> Map model</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../map/importing/index.html"><strong aria-hidden="true">6.1.</strong> Importing</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../map/importing/convert_osm.html"><strong aria-hidden="true">6.1.1.</strong> convert_osm</a></li><li class="chapter-item expanded "><a href="../map/importing/geometry.html"><strong aria-hidden="true">6.1.2.</strong> Road/intersection geometry</a></li><li class="chapter-item expanded "><a href="../map/importing/rest.html"><strong aria-hidden="true">6.1.3.</strong> The rest</a></li></ol></li><li class="chapter-item expanded "><a href="../map/edits.html"><strong aria-hidden="true">6.2.</strong> Live edits</a></li><li class="chapter-item expanded "><a href="../map/misc.html"><strong aria-hidden="true">6.3.</strong> Misc</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="spacer"></li></ol></li><li class="chapter-item expanded "><a href="../project/index.html"><strong aria-hidden="true">8.</strong> Project</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../project/roadmap.html"><strong aria-hidden="true">8.1.</strong> Roadmap</a></li><li class="chapter-item expanded "><a href="../project/motivations.html"><strong aria-hidden="true">8.2.</strong> Motivations</a></li><li class="chapter-item expanded "><a href="../project/history/index.html"><strong aria-hidden="true">8.3.</strong> History</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../project/history/backstory.html"><strong aria-hidden="true">8.3.1.</strong> Backstory</a></li><li class="chapter-item expanded "><a href="../project/history/year1.html"><strong aria-hidden="true">8.3.2.</strong> Year 1</a></li><li class="chapter-item expanded "><a href="../project/history/year2.html"><strong aria-hidden="true">8.3.3.</strong> Year 2</a></li><li class="chapter-item expanded "><a href="../project/history/year3.html"><strong aria-hidden="true">8.3.4.</strong> Year 3</a></li></ol></li><li class="chapter-item expanded "><a href="../project/CHANGELOG.html"><strong aria-hidden="true">8.4.</strong> Full CHANGELOG</a></li><li class="chapter-item expanded "><a href="../project/references.html"><strong aria-hidden="true">8.5.</strong> References</a></li></ol></li></ol>
|
|
</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="#map-model" id="map-model">Map model</a></h1>
|
|
<p>A/B Street builds a rich representation of a city map using OpenStreetMap (OSM)
|
|
and other sources. This chapter describes how.</p>
|
|
<p>TODO: Integrate pictures from
|
|
<a href="https://docs.google.com/presentation/d/1cF7qFtjAzkXL_r62CjxBvgQnLvuQ9I2WTE2iX_5tMCY/edit?usp=sharing">these slides</a>.</p>
|
|
<p><a href="https://youtu.be/chYd5I-5oyc?t=439">This recorded presentation</a> covers some of
|
|
this.</p>
|
|
<h2><a class="header" href="#the-map" id="the-map">The map</a></h2>
|
|
<p>A single city is broken down into different pieces...</p>
|
|
<p>A/B Street comes with a few maps, each defined by a bounding/clipping polygon
|
|
for some portion of Seattle. Each map has these objects:</p>
|
|
<ul>
|
|
<li><strong>Roads</strong>: A single road connects two intersections, carrying OSM metadata and
|
|
containing some child lanes.</li>
|
|
<li><strong>Lanes</strong>: An individual lane of traffic. Driving (any vehicle), bus-only, and
|
|
bike-only lanes have a direction. On-street parking lanes don't allow any
|
|
movement, and they have some number of parking spots. Sidewalks are
|
|
bidirectional.</li>
|
|
<li><strong>Intersections</strong>: An intersection has references to all of the incoming and
|
|
outgoing lanes. Most intersections have a stop sign or traffic signal policy
|
|
controlling movement through it.
|
|
<ul>
|
|
<li><strong>Border</strong> intersections on the edge of the map are special places where
|
|
agents may appear or disappear.</li>
|
|
</ul>
|
|
</li>
|
|
<li><strong>Turns</strong>: A turn connects one lane to another, via some intersection.
|
|
(Sidewalks are bidirectional, so specifying the intersection is necessary to
|
|
distinguish crosswalks at each end of a sidewalk.)</li>
|
|
<li><strong>Buildings</strong>: A building has a position, OSM metadata, and a <strong>front path</strong>
|
|
connecting the edge of the building to the nearest sidewalk. Most trips in A/B
|
|
Street begin and end at buildings. Some buildings also contain a number of
|
|
off-street parking spots.</li>
|
|
<li><strong>Area</strong>: An area has geometry and OSM metadata and represents a body of
|
|
water, forest, park, etc. They're just used for drawing.</li>
|
|
<li><strong>Bus stop</strong>: A bus stop is placed some distance along a sidewalk, with a
|
|
pointer to the position on the adjacent driving or bus lane where a bus stops
|
|
for pick-up.</li>
|
|
<li><strong>Bus route</strong>: A bus route has a name and a list of stops that buses will
|
|
cycle between. In the future, they'll include information about the
|
|
frequency/schedule of the route.</li>
|
|
<li><strong>Parking lot</strong>: A parking lot is connected to a road, has a shape, and has
|
|
some internal driving "aisles." The number and position of individual parking
|
|
spots is auto-generated.</li>
|
|
</ul>
|
|
<h2><a class="header" href="#coordinate-system" id="coordinate-system">Coordinate system</a></h2>
|
|
<p>A/B Street converts (longitude, latitude) coordinates into a simpler form.</p>
|
|
<ul>
|
|
<li>An (x, y) point starts with the top-left of the bounding polygon as the
|
|
origin. Note this is screen drawing order, not a Cartesian plane (with Y
|
|
increasing upwards) -- so angle calculations account for this.</li>
|
|
<li>The (x, y) values are f64's trimmed to a few decimal places, with way more
|
|
precision than is really needed. These might become actual fixed-point
|
|
integers later, but for now, a <code>Pt2D</code> skirts around Rust's limits on f64's by
|
|
guaranteeing no NaN's or infinities and thus providing the full <code>Eq</code> trait.</li>
|
|
<li>A few places in map conversion compare points using different thresholds,
|
|
usually below 1 meter. Ideally these epsilon comparisons could be eliminated
|
|
in favor of a fixed-point integer representation, but for now, explicit
|
|
thresholds are useful.</li>
|
|
</ul>
|
|
<h2><a class="header" href="#invariants" id="invariants">Invariants</a></h2>
|
|
<p>Ideally, the finalized maps would satisfy a list of invariants, simplifying the
|
|
traffic simulation and drawing code built on top. But the input data is quite
|
|
messy and for now, most of these aren't quite guaranteed to be true.</p>
|
|
<ul>
|
|
<li>Some minimum length for lanes and turns. Very small lanes can't be drawn, tend
|
|
to break intersection polygons, and may lead to gridlocked traffic.</li>
|
|
<li>Some guarantees that positions along adjacent lanes actually match up, even
|
|
though different lanes on the same road may have different lengths. Examples
|
|
include the position of a bus stop on the sidewalk and bus lane matching up.
|
|
<ul>
|
|
<li>Additionally, parking lanes without an adjacent driving lane or bus stops
|
|
without any driving or bus lanes make no sense and should never occur.</li>
|
|
</ul>
|
|
</li>
|
|
<li>Connectivity -- any sidewalk should be reachable from any other, and most
|
|
driving lanes should be accessible from any others. There are exceptions due
|
|
to border intersections -- if a car spawns on a highway along the border of
|
|
the map, it may be forced to disappear on the opposite border of the map, if
|
|
the highway happens to not have any exits within the map boundary.</li>
|
|
</ul>
|
|
<h2><a class="header" href="#connectivity" id="connectivity">Connectivity</a></h2>
|
|
<p>For a single mode, each lane is connected to two intersections. Turns connect
|
|
two lanes. There are no turns between sidewalks and driving/bike/bus lanes.</p>
|
|
<p>All buildings and parking lots have driveways. This must connect to a sidewalk,
|
|
allowing pedestrians to enter/exit that object. The driveway OPTIONALLY connects
|
|
to the nearest driveable lane. This allows cars to enter/exit that object for
|
|
parking.</p>
|
|
<p>Public transit stops are located somewhere on a sidewalk. They're associated
|
|
with a driveable position where the bus or train stops. In the future, this will
|
|
need to account for dedicated surface-level platforms and for underground
|
|
transit stations, likely associated with a building.</p>
|
|
<p>There's a concept of "parking blackholes." If you treat every road as
|
|
bidirectional without access restrictions, then the graph is connected. But the
|
|
more detailed view has to factor in one-way roads and things near the map
|
|
border. These blackholes influence where cars will try to look for parking
|
|
(since we don't want them entering a blackhole and getting stuck) and also, for
|
|
temporary/unintentional reasons, where pedestrian<->bicycle transitions will
|
|
happen.</p>
|
|
|
|
</main>
|
|
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|
<!-- Mobile navigation buttons -->
|
|
|
|
<a rel="prev" href="../dev/api.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
<i class="fa fa-angle-left"></i>
|
|
</a>
|
|
|
|
|
|
|
|
<a rel="next" href="../map/importing/index.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
<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">
|
|
|
|
<a rel="prev" href="../dev/api.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
<i class="fa fa-angle-left"></i>
|
|
</a>
|
|
|
|
|
|
|
|
<a rel="next" href="../map/importing/index.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
<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>
|