1 package org.opentrafficsim.road.network.route;
2
3 import java.io.Serializable;
4 import java.util.Map;
5
6 import org.djunits.unit.LengthUnit;
7 import org.opentrafficsim.core.gtu.GTUType;
8 import org.opentrafficsim.core.network.LateralDirectionality;
9 import org.opentrafficsim.road.network.lane.CrossSectionElement;
10 import org.opentrafficsim.road.network.lane.CrossSectionLink;
11 import org.opentrafficsim.road.network.lane.Lane;
12
13 /**
14 * A RouteNavigator helps to navigate on a route. In addition, helper methods are available to see if the GTU needs to change
15 * lanes to reach the next link on the route.
16 * <p>
17 * Copyright (c) 2013-2015 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
18 * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
19 * <p>
20 * $LastChangedDate: 2015-07-16 10:20:53 +0200 (Thu, 16 Jul 2015) $, @version $Revision: 1124 $, by $Author: pknoppers $,
21 * initial version Jul 22, 2015 <br>
22 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
23 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
24 */
25 public abstract class AbstractLaneBasedRouteNavigator implements LaneBasedRouteNavigator, Serializable
26 {
27 /** */
28 private static final long serialVersionUID = 20150722L;
29
30 /** Return value of suitability when no lane change is required withing the time horizon. */
31 public static final Length.Rel NOLANECHANGENEEDED = new Length.Rel(Double.MAX_VALUE, LengthUnit.SI);
32
33 /** Return value of suitability when a lane change is required <i>right now</i>. */
34 public static final Length.Rel GETOFFTHISLANENOW = new Length.Rel(0, LengthUnit.SI);
35
36 /**
37 * Compute the suitability of a lane from which lane changes are required to get to the next point on the Route.<br>
38 * This method weighs the suitability of the nearest suitable lane by (m - n) / m where n is the number of lane changes
39 * required and m is the total number of lanes in the CrossSectionLink.
40 * @param startLane Lane; the current lane of the GTU
41 * @param remainingDistance double; distance in m of GTU to first branch
42 * @param suitabilities Map<Lane, Double>; the set of suitable lanes and their suitability
43 * @param totalLanes integer; total number of lanes compatible with the GTU type
44 * @param direction LateralDirectionality; the direction of the lane changes to attempt
45 * @param gtuType GTUType; the type of the GTU
46 * @return double; the suitability of the <cite>startLane</cite> for following the Route
47 */
48 protected final Length.Rel computeSuitabilityWithLaneChanges(final Lane startLane, final double remainingDistance,
49 final Map<Lane, Length.Rel> suitabilities, final int totalLanes, final LateralDirectionality direction,
50 final GTUType gtuType)
51 {
52 /*-
53 * The time per required lane change seems more relevant than distance per required lane change.
54 * Total time required does not grow linearly with the number of required lane changes. Logarithmic, arc tangent
55 * is more like it.
56 * Rijkswaterstaat appears to use a fixed time for ANY number of lane changes (about 60s).
57 * TomTom navigation systems give more time (about 90s).
58 * In this method the returned suitability decreases linearly with the number of required lane changes. This
59 * ensures that there is a gradient that coaches the GTU towards the most suitable lane.
60 */
61 int laneChangesUsed = 0;
62 Lane currentLane = startLane;
63 Length.Rel currentSuitability = null;
64 while (null == currentSuitability)
65 {
66 laneChangesUsed++;
67 if (currentLane.accessibleAdjacentLanes(direction, gtuType).size() == 0)
68 {
69 return GETOFFTHISLANENOW;
70 }
71 currentLane = currentLane.accessibleAdjacentLanes(direction, gtuType).iterator().next();
72 currentSuitability = suitabilities.get(currentLane);
73 }
74 double fraction = currentSuitability == NOLANECHANGENEEDED ? 0 : 0.5;
75 int notSuitableLaneCount = totalLanes - suitabilities.size();
76 return new Length.Rel(remainingDistance * (notSuitableLaneCount - laneChangesUsed + 1 + fraction)
77 / (notSuitableLaneCount + fraction), LengthUnit.SI);
78 }
79
80 /**
81 * Determine how many lanes on a CrossSectionLink are compatible with a particular GTU type.<br>
82 * TODO: this method should probably be moved into the CrossSectionLink class
83 * @param link CrossSectionLink; the link
84 * @param gtuType GTUType; the GTU type
85 * @return integer; the number of lanes on the link that are compatible with the GTU type
86 */
87 protected final int countCompatibleLanes(final CrossSectionLink link, final GTUType gtuType)
88 {
89 int result = 0;
90 for (CrossSectionElement cse : link.getCrossSectionElementList())
91 {
92 if (cse instanceof Lane)
93 {
94 Lane l = (Lane) cse;
95 if (l.getLaneType().isCompatible(gtuType))
96 {
97 result++;
98 }
99 }
100 }
101 return result;
102 }
103 }