Make the one-mode path guesses more precise in their start/end locations. Noticeable effect is in the freeform agent spawner, the paths actually go between buildings now, instead of lane starts.

data/MANIFEST.json

@@ -637,15 +637,15 @@
       "size_bytes": 59144729
     },
     "data/system/seattle/prebaked_results/lakeslice/weekday.bin": {
-      "checksum": "06f5cf09a3c67d9487eb35823f95a920",
+      "checksum": "451dfa40686cc5111922f5905ce03197",
       "size_bytes": 66439671
     },
     "data/system/seattle/prebaked_results/montlake/car vs bike contention.bin": {
-      "checksum": "1f8cd9511798d39539f4e6feb933d645",
+      "checksum": "d1bb6deda465f6ff1705034ba41ff806",
       "size_bytes": 5277
     },
     "data/system/seattle/prebaked_results/montlake/weekday.bin": {
-      "checksum": "0bff5ccfad021b99b3266886ba3aafa8",
+      "checksum": "6a8b47cb8afe5cf44ccd77e7e4fdfb00",
       "size_bytes": 8533785
     },
     "data/system/seattle/scenarios/ballard/weekday.bin": {

headless/src/main.rs

@@ -393,6 +393,8 @@ struct AgentPosition {
     ///   transit stop.
     /// - The value might be slightly undercounted or overcounted if the path crosses into or out
     ///   of an access-restricted or capped zone.
+    /// - At the very end of a driving trip, the agent may wind up crossing slightly more or less
+    ///   than the total path length, due to where they park along that last road.
     distance_crossed: Distance,
     /// None for buses
     person: Option<PersonID>,

sim/src/lib.rs

@@ -363,7 +363,13 @@ impl DrivingGoal {
         match self {
             DrivingGoal::ParkNear(b) => match constraints {
                 PathConstraints::Car => {
-                    Some(Position::start(map.find_driving_lane_near_building(*b)))
+                    let driving_lane = map.find_driving_lane_near_building(*b);
+                    let sidewalk_pos = map.get_b(*b).sidewalk_pos;
+                    if map.get_l(driving_lane).parent == map.get_l(sidewalk_pos.lane()).parent {
+                        Some(sidewalk_pos.equiv_pos(driving_lane, map))
+                    } else {
+                        Some(Position::start(driving_lane))
+                    }
                 }
                 PathConstraints::Bike => Some(map.get_b(*b).biking_connection(map)?.0),
                 PathConstraints::Bus | PathConstraints::Train | PathConstraints::Pedestrian => {

sim/src/make/spawner.rs

@@ -306,6 +306,10 @@ pub enum TripEndpoint {
 }
 
 impl TripEndpoint {
+    /// Figure out a single PathRequest that goes between two TripEndpoints. Assume a single mode
+    /// the entire time -- no walking to a car before driving, for instance. The result probably
+    /// won't be exactly what would happen on a real trip between the endpoints because of this
+    /// assumption.
     pub fn path_req(
         from: TripEndpoint,
         to: TripEndpoint,
@@ -361,7 +365,7 @@ impl TripEndpoint {
         }
     }
 
-    pub(crate) fn pos(self, mode: TripMode, from: bool, map: &Map) -> Option<Position> {
+    fn pos(self, mode: TripMode, from: bool, map: &Map) -> Option<Position> {
         match mode {
             TripMode::Walk | TripMode::Transit => (if from {
                 self.start_sidewalk_spot(map)