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Understanding speed behaviours, speed limit compliance, and road characteristics in Leeds

Research by Long Chen and Ed Manley uses data provided by Compass IoT to provide an overview of speed behaviours, speed limit compliance and road characteristics in Leeds.


Importance of Speed behaviours

Speed behaviours of vehicles are important facets in transport planning, road safety and urban livability. There are also several critical social and environmental aspects linked with speed behaviors, e.g., excessive carbon emissions.

Speed limit compliance

Adherence on posted road speed limits would have positive effects on traffic safety, road capacity, and traffic congestion, etc.

Measures of speed behaviours

Prior studies are often conducted by questionnaire survey; limited sites observation; and simulated driving environment to capture vehicle speeds and driver’s speed behaviours.

Study Data

For this study we used vehicle trajectories with travel speeds and acceleration indicators, provided by Compass IoT. This dataset is available for access on the CDRC data repository. The dataset is available for several UK cities. The data used in this study focuses on Leeds only, and contains 3,008,530 individual point records within 44,321 unique journeys, during October 2023.

The Gaps

• There is an absence of studies capturing speed behaviours and characteristics for large volume of vehicle trajectories on a larger geographical scale.

• There is a lack of knowledge between speed behaviours, road characteristics and urban environment at finer-granularity.


• Measures of speed selection (including adherence with speed limit) and acceleration behaviours (e.g. slow / rapid) extracted

• Mean measures computed over time (hour, day) and by road segment

• Quantiles used to select boundaries for assessing acceleration and deceleration behaviours, including extreme behaviours (Q1, Q4)


Speed behaviours over time

Temporal variation of speed, acceleration, deceleration in Leeds show that fastest speeds occur during the night-time; Rapid acceleration and deceleration events are more common during the daytime than at night

            Figure 1: Temporal variation of speed by quartiles, Figure 2: Temporal variation of Acceleration, Deceleration by quartiles

Speed selection and adherence over space

Lower speeds observed in. dense road networks and urban areas; Higher speeds observed on highways and major roads.

Figure 3: Average speed at Road segments               Figure 4: Adherence rate at Road segments

Better adherence in dense road networks, and urban areas; Worse adherence on 20mph zones and pedestrianised areas

Acceleration, and Deceleration

Average acceleration, deceleration maps illustrate that higher acceleration and deceleration road segments are located at main roads, particularly around junctions, and suburban residential areas

Roads segments with extreme acceleration, and deceleration behaviours usually accommodate in dense road network, and junctions of road networks.


• Results show distinctive speed limit adherence, acceleration, and deceleration characteristics in road hierarchy and urban areas, highlighting the potential for analysing speed behaviours in urban settings.

• Specifically, lower speed limit adherence behaviours generally occur in roads with lower speed limit, and minor and local roads, in suburban residential areas; Extreme acceleration and deceleration behaviours are found in dense road network, and entries and exits of major roads (e.g. motorways).

• The exploration of speed behaviours opens up new opportunities for considering urban mobility and design, and opportunities for understanding the latent mechanisms and factors influencing these behaviours.

Use the data

Compass Connected Car Vehicle Trajectories and Behaviours data is available via our data service – The dataset, supplied by Compass IoT, is composed of vehicle journeys undertaken in several UK cities during the month of October 2023.