Methods and frameworks: The model process

Using the prepared data sources as inputs, the model provides a projected estimation of the potential authorized police strength needed to accommodate the dynamic growth occurring within Coquitlam and Port Coquitlam. This estimation is measured as a number of full-time equivalent (FTE) sworn RCMP member positions, and is developed following a series of analytical steps.

Authorized strength: Full-time equivalent allocation

The initial phase of this model considers the current allocation of RCMP resourcing for the area in question. Each year, the British Columbia provincial government publishes a report on police strength, reporting the authorized strength for each municipality and provincial jurisdiction in the province. The authorized strength is measured in FTE positions, and represents the total number of both sworn members and sworn civilians designated for Coquitlam and Port Coquitlam, but does not include other municipal support staff (Ministry of Public Safety and Solicitor General, 2009, 2015). The initial model input totals the 2008 authorized strength for Coquitlam (142) and Port Coquitlam (64), and maintains the total proportion of members as divided by municipality throughout the model.

The model builds upon the current relationship between police resources, land use development, and police records, requiring the initial authorized strength (as measured at the model start point – in this case, 2008) as data input. Recognizing that the current

resourcing counts may not represent an appropriate or ideal starting figures, these numbers may be adjusted to view the potential impact that more or fewer initial resources may have on policing requirements in later years. This feature is specifically relevant within Coquitlam and Port Coquitlam: if the detachment is underserved by officers at the model start, this shortage in FTEs is maintained throughout the model. By adjusting the initial police strength, output may depict alternative scenarios with higher levels of police resources maintained throughout. This modeling stage also provides the opportunity to input any actual or expected increases in police resources throughout the modeling timeframe, allowing for a comparison of potential anticipated needs versus actual anticipated resources. Police strength per year, measured in FTEs, is represented within the model as:

( ) Where

1, ⋯ , 7 7

2009 2015 Workload by environmental feature

The next step in the modelling process recognizes that it takes different amounts of policing resources to respond to calls for service at different locations. This can be due to the physical features of the land use - for example, high-rise condominiums often have increased security measures, locked stairwells, and elevators that do not permit access to floors without passes. These additional measures may offer increased security to residents, but may also increase the amount of time required for a police officer to access a particular unit. Other facilities, such as parks or recreation sites, may offer ease of access and clear line of sight, reducing the barriers to on-scene access and work. With this in mind, the second phase of the modeling process introduces categories of land use and environmental features, and weighs each category according to the amount of time resources required to respond to calls for service at these locations.

First, all built environmental data for Coquitlam and Port Coquitlam is compiled and grouped according to feature type. Grouping decisions are informed from the results of a local area analysis of crime within the built environment, and include four broad categories

of land use (residential, commercial, CIR and other¹⁵), as well as two broad road-based categories (intersections and blocks). Broad land use categories are broken into sub-categories based on the actual use of the property, and informed by the local area analysis (see Chapter 2 and Chapter 3). Broad road-based categories are divided based on proximity to arterial routes. Environmental features are represented within the model as follows:

, Where

1, ⋯ , 6 6

1, ⋯ , 7 7

2009 2015

A weighting measure called Workload per Call is then developed using the Coquitlam RCMP Detachment's 2009 CAD records. The CAD records, as described above, are cleaned, geocoded, and linked to detailed land use and road type information.

From this data, all calls for service are selected where an officer was dispatched to the scene, and where associated time on scene attributes were recorded (n = 23,491). For every environmental feature classification and sub-category, the median time spent on-scene is determined. This data is then standardized by the overall median time on on-scene for all calls for service within the study area. The standardized measure is used as a proxy for workload per call. Environmental features that require more time or resources are weighted proportionally higher than those that require a lesser workload. This standardized weight is represented within the modeling framework as ( ) and is calculated for each environmental feature category and sub-category ( ).

Police records by environmental feature

In an effort to account for the varying impact that environmental features have on the distribution of police records, the third modelling phase incorporates current police

15 The broad land use classification of “other” is a compiled category including the very small percentage of lots not falling into the three main categories of analysis. Land uses within this category include farm, SOFA (common areas within stratified units), industrial and TCU (transportation, communication and utility) land uses.

record data into the modelling process. The data included as primary input is the 2008 PRIME records for Coquitlam and Port Coquitlam. As these records are linked with the local environmental feature datasets, police records are grouped according to each environmental feature category ( ) to calculate a rate of records per unit; a value denoted within the model as ( ).

Urban growth estimates

Stage four of the model projects potential urban growth over a set number of years, based on past trends in urban development. The current model uses the 2008 and 2009 BCAA land use information for the cities of Coquitlam and Port Coquitlam to estimate future land use-based patterns from 2010 to 2015. Road network changes are estimated between 2008 and 2014 input years, and projected based on this relationship for 2015. All growth models are based on a logarithmic function, which projects a quick initial change prior to levelling out. This growth formula was selected to represent the patterns of development experienced within the Greater Vancouver area, which is expected to continue in incremental stages (City of Coquitlam, 2008). The urban growth as projected within the model is described as follows:

, ln ^∗

Where

∗

2008 2008 , 2008 2014

The model requires an estimation of the number of units within each environmental feature category and sub-category for each of the years of interest as explored in the model. These projections can be manually adjusted upwards or downwards on an individual basis or using an alternative growth formula, or (preferably) fit to match city plans for the years of study through consultation with city planners.

Estimation of police records by environmental feature

Following the estimation of land use growth and development within the study area, stage five of the modelling process calculates a projected count of police records ( _, ) for

each environmental feature category ( ), for 2009 to 2015. This is accomplished by multiplying the projected number of units of a given environmental feature by the initial rate of records per unit for the same feature category. The resulting output is an estimate for the number of police records associated with each type of environmental feature for each of the target years of this study.

This is described within the model as follows:

, ∗ _,

Total projected police records for a given year ( ) can then be calculated as follows:

∗ _,

Estimates of Workload

The final stage of the model uses several steps to arrive at an estimation of the police strength ( ), required for Coquitlam and Port Coquitlam for each projected year.

First, an adjusted workload per environmental feature measure is calculated, ( _, ), to take into account the varied cost associated with events at different environmental features.

This is calculated as follows:

, ∗ _,

This weighted workload per environmental feature is then summed to arrive at a total workload for a given year ( ):

∗ _,

At this point, the model uses the initial ratio of full-time equivalents to Workload, as identified in 2008, to develop a new projected FTE estimate ( ) for each modelled year.

This calculation provides the total FTEs, and can be further divided to present the total

proportion of FTEs allocated to each municipality (Coquitlam and Port Coquitlam respectively). This is represented in the model as follows:

∗ ^∗

∗

Where

∗ 2008

The total model, then, can be conceptualized as follows:

∗ ∗ _, ∗ ∑ ∗ ∗^∗ _, ^∗

Where

1, ⋯ , 7 7

2009 2015

,

1, ⋯ , 6 6

∗ 2008