Ungap the Map ideas

[dabreegster]

• add a count of businesses along the route
• add some idea of directness / ease of wayfinding

[dabreegster]

@hussein-mahfouz

[Hussein-Mahfouz]

Some notes I had on route directness (based on conversations with you and @juanfonsecaLS1):

• more turns leads to cognitive overhead. Direct paths are preferable for cyclists
• BUT we can have a straight path that is much longer than the shortest path
• we want a metric that combines path length with number of turns to get a perceived shortest path

Calculating number of turns

1. Change in Bearing

Paper: Turn calculations for the indoor application of the fewest turns path algorithm

Figure 2 shows a basic turn calculation algorithm. It calculates the angle between 3 consecutive nodes, and if it is above a defined threshold then we have a turn

2. Number of options at Node / Intersection

From a wayfinding perspective, we should only consider it a turn if it is a node/interestion with more than one allowable turn

Using number of turns to calculate perceived route length

Paper: The role of turns in pedestrian route choice: A clarification

"Based on prior findings from pedestrian path choice studies, we can state that the “perceived” length of a route (c) depends both on the route's objective length (l) and the number of turns along the route (t), such that c = l + σt, where σ is a scaling factor that standardizes turns into distance equivalent units. We can additionally denote paths that are perceived to be shortest between a given origin and destination in terms of both distance and turns combined as i = min (c), and paths that are simply shortest in terms of distance alone as j = min (l). For any pedestrian origin-destination pair in a street network, we can thus examine whether the shortest objective route j also happens to be the shortest perceived route i, or whether alternatives exist where a lower perceived length (c) can be found on different routes, which may include fewer turns than the shortest length route j. We can quantify the difference in perceived length (c) on both the objectively shortest distance route j and the shortest available perceived length route i by a score z, such that z = (c(j) − c(i))/c(j). In other words, z describes how much (in percentage terms) the “perceived” length of the route can be reduced from the shortest objective route by using an alternative route that involves fewer turns."

"To factor in a distance- equivalent penalty for each turn (σ), we used the estimated distance- equivalent effects for turns by Sevtsuk et al. (2021), who reported one turn to be equivalent to 62.3 m in San Francisco."