An Empirical Evaluation of Measures to Improve
Bus Service Reliability
Performance Metrics and a Case Study in Stockholm
Masoud Fadaei Oshyani and Oded Cats
Service unreliability: A vicious cycle
Line 1, Stockholm
Urban
mobility
strategy
Bus preferential measures
• Running time
•
Right of way
•
Street layout
•
Demand management
• Crossing time
•
Priority in time
•
Priority in space
• Dwell time
•
Stop layout
•
Fare validation
•
[stop consolidation]
Reliability
A series of field experiments
RETT2
• Experiment – L1
• Focus on regularity, decentalization
RETT3
• Experiment – L1; L3
• Clean-operations, control center actions
• Led to its incorporation in the tendering process
RETT4
• Experiment – L4
• Additional measures – boarding, priority
• Support full-scale implementation
Adaptive headway-control strategy
•
Various strategies were evaluated using BusMezzo
•
The most promising strategy
•
Try to remain in the
middle
with respect to the preceding and
successive buses
• Adjust
your
speed
if possible
• Disregard
the
timetable
𝐸𝑇
𝑠,𝑙𝑘= max min 𝐴𝑇
𝑠,𝑙𝑘−1+
𝐴𝑇
𝑚,𝑙𝑘+1
+ 𝑆𝑅𝑇
𝑚,𝑠
− 𝐴𝑇
𝑠,𝑙𝑘−1Decentralized headway control
+1
-1
+2
0
0
0
[speed up
if possible]
hold/
slow down
hold/
slow
down
Also at the aggregate level –
Headway distribution
• Route
: 31 stops along 12km, cross-radial
inner-city line
• Commercial speed
: 12.56 km/hr
• Frequency
: 4-6 minutes all day long
• Vehicle
: Articulated buses
• Demand
: 65,000 passengers per day
Line 4 Stockholm
•
Measures
Introducing bus
lanes
on some line sections
Cancelling
4 stops
Running based on
regularity
Improving
transit signal priority
Allowing restricted
boarding
from the third door
Street layout changes
•
Period: 17-03-2014 – 19-06-2014
•
AVL (100%) and APC (15%) data
•
Compare with same period in 2013
Line 4 Stockholm
tar y M ea su res
Link related Operation
& Control Stop related
V eh ic le p erf or m an ce A V L APC / AF C Running time Dwell time
Reliability Demand Pattern
V eh ic le tim es Pass en ger tim es
Total trip time
In-vehicle time Waiting time
Total travel time
St
ep 1
St
ep 2
3
Evaluation
framewo
rk
•
Average passenger waiting time
1
𝑏
𝑘,𝑠𝑖 𝑆 −1 𝑖=1 𝑘∈𝐾𝑏
𝑘,𝑠𝑖 𝑆 −1 𝑖=1 𝑘∈𝐾⋅
ℎ
𝑘,𝑠𝑖 𝑜2
•
Average passenger in-vehicle time
1
𝑙
𝑘,𝑠𝑖 𝑆 −1 𝑖=1 𝑘∈𝐾𝑙
𝑘,𝑠𝑚∗ 𝑡
𝑘,𝑠𝑑𝑤𝑒𝑙𝑙𝑚+ 𝑡
𝑘,𝑠 𝑚 𝑟𝑢𝑛𝑛𝑖𝑛𝑔 𝑆 −1 𝑚=1 𝑘∈𝐾•
Average generalized passenger in-vehicle time
1
𝑙
𝑘,𝑠𝑖 𝑆 −1 𝑖=1 𝑘∈𝐾𝑃𝐼𝑉𝑇
𝑘,𝑠𝑖 𝑆 −1 𝑖=1 𝑘∈𝐾 min 𝛾𝑘,𝑠𝑖, 1 ∗ 𝑣𝑘𝑠𝑒𝑎𝑡 ∗ 𝛽𝑘,𝑠𝑠𝑖𝑡𝑡𝑖𝑛𝑔𝑖 + max 0, 𝛾𝑘,𝑠𝑖 − 1 (𝑙𝑘,𝑠𝑖 − 𝑣𝑘𝑠𝑒𝑎𝑡) ∗ 𝛽𝑘,𝑠𝑠𝑡𝑎𝑛𝑑𝑖𝑛𝑔𝑖 ∙ 𝑡𝑘,𝑠𝑑𝑤𝑒𝑙𝑙𝑖 + 𝑡𝑘,𝑠𝑟𝑢𝑛𝑛𝑖𝑛𝑔𝑖Estimating OD matrix from APC
More reliable fleet operations
Afternoon peak period
Total running time
Average trip time
90
thtrip time
Significantly fewer extremely long trips
