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7 August 2026
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Featured FRI Magazine article: Fire station planning principles: Calculating optimal siting by the late Previn D Govender
This week’s featured Fire and Rescue International magazine article is: Fire station planning principles: Calculating optimal siting by the late Previn D Govender, divisional head: strategy and planning, City of Ekurhuleni Disaster and Emergency Management Services, at the time of writing the article (FRI Vol 4 no 1). We will be sharing more technical/research/tactical articles from Fire and Rescue International magazine on a weekly basis with our readers to assist in technology transfer. This will hopefully create an increased awareness, providing you with hands-on advice and guidance. All our magazines are available free of charge in PDF format on our website and online at ISSUU. We also provide all technical articles as a free download in our article archive on our website.
Fire station planning principles: Calculating optimal siting
By the late Previn D Govender, divisional head: strategy and planning, City of Ekurhuleni Disaster and Emergency at the time of writing the article
In this third part of the four part series on fire station planning principles, we focus on the methodology used in motivating planning principles such as South African Standard (SANS) 10090, National Fire Protection Association (NFPA) 1710 and Geographic Information Systems (GIS).
The planning for and location of fire stations sites must be informed by methodical and logical analysis of key factors and well supported by current and historical data in order to lead to credible and informed decisions conclusive and sufficient enough to meet current and future demands.
Fire station planning principles: Calculating optimal siting
By the late Previn D Govender, divisional head: strategy and planning, City of Ekurhuleni Disaster and Emergency at the time of writing the article
In this third part of the four part series on fire station planning principles, we focus on the methodology used in motivating planning principles such as South African Standard (SANS) 10090, National Fire Protection Association (NFPA) 1710 and Geographic Information Systems (GIS).
The planning for and location of fire stations sites must be informed by methodical and logical analysis of key factors and well supported by current and historical data in order to lead to credible and informed decisions conclusive and sufficient enough to meet current and future demands.
SANS 10090 methodology
Using the requirements of SANS 10090 required attendance times at fires (refer table 2 in previous article), in order to determine the fire response coverage area the key factors that are used for computing the plotting of future fire station locations are:
a. The travel time requirement for the highest risk
b. Estimated speed of the appliance compensating for complexities of street grids and networks
c. The distance that will be covered when multiplying the above two factors in order ie distance (km) = speed (km/h x time (hours)
Once the distance that can be travelled is known, the next step is to establish the coverage area by extending the linear distance calculated from the centre point in the form of a regular polygon, in this case a six-sided polygon or hexagon.
Once the polygon has been established; it is then possible to work out the square kilometres that can be covered by using the formula (fig 2) below:
Using the requirements of SANS 10090 required attendance times at fires (refer table 2 in previous article), in order to determine the fire response coverage area the key factors that are used for computing the plotting of future fire station locations are:
a. The travel time requirement for the highest risk
b. Estimated speed of the appliance compensating for complexities of street grids and networks
c. The distance that will be covered when multiplying the above two factors in order ie distance (km) = speed (km/h x time (hours)
Once the distance that can be travelled is known, the next step is to establish the coverage area by extending the linear distance calculated from the centre point in the form of a regular polygon, in this case a six-sided polygon or hexagon.
Once the polygon has been established; it is then possible to work out the square kilometres that can be covered by using the formula (fig 2) below:
Figure 2: Formula for calculating square kilometre area
Example of fire response coverage area calculation using SANS 10090
A worked example of coverage area for a fire station to meet Category ‘A’ fire risk travel time of five minutes based on the estimated appliance speed of 30km/h would look like:
STEP 1: Calculate linear travel distance
Distance = speed x time
Where:
d=?
s= 30km/h
t = ,08 hours ie five minutes travel time required for category A fire risk divided by 60 minutes
Thus:
d = 30 x 0,08 = 2,4 km is the distance that can be travelled in five minutes at 30 km/h.
STEP 2: Establish polygon
Example of fire response coverage area calculation using SANS 10090
A worked example of coverage area for a fire station to meet Category ‘A’ fire risk travel time of five minutes based on the estimated appliance speed of 30km/h would look like:
STEP 1: Calculate linear travel distance
Distance = speed x time
Where:
d=?
s= 30km/h
t = ,08 hours ie five minutes travel time required for category A fire risk divided by 60 minutes
Thus:
d = 30 x 0,08 = 2,4 km is the distance that can be travelled in five minutes at 30 km/h.
STEP 2: Establish polygon
STEP 3: Establish polygon
STEP 4: Factor 25 percent deduction allowance
SANS advises that an allowance of 25 percent must be deducted in order to make provision for complexities of street grid networks.
= 15,02 km2 – 25 percent
= 11km2 is the area to be covered with five minute response window travelling at 30km/h.
STEP 5: Repeat step 1 to Step 4 for B, C and D categories
Using the same travel speed (30km/h) but the different maximum time requirements for each remaining fire risk category; calculate the fire response coverage areas for B, C and D fire risk categories.
STEP 6: Overlay polygons on map
Consolidate polygons for each risk category and overlay on map to provide indicative fire response coverage for each risk category. Map and polygon shown below only for illustrative purposes
SANS advises that an allowance of 25 percent must be deducted in order to make provision for complexities of street grid networks.
= 15,02 km2 – 25 percent
= 11km2 is the area to be covered with five minute response window travelling at 30km/h.
STEP 5: Repeat step 1 to Step 4 for B, C and D categories
Using the same travel speed (30km/h) but the different maximum time requirements for each remaining fire risk category; calculate the fire response coverage areas for B, C and D fire risk categories.
STEP 6: Overlay polygons on map
Consolidate polygons for each risk category and overlay on map to provide indicative fire response coverage for each risk category. Map and polygon shown below only for illustrative purposes
NFPA 1710 methodology
Taking into account that the NFPA 1710 is provision of SANS 10090, the American system considers the distribution of fire stations based on the required response times (table 3) for the area protected rather than risk protected and on the Fire
Suppression Rating Schedule (FSRS), which is an analysis tool of the Public Protection Classification (PPC™) programme of the Insurance Service Office-USA (ISO).
Taking into account that the NFPA 1710 is provision of SANS 10090, the American system considers the distribution of fire stations based on the required response times (table 3) for the area protected rather than risk protected and on the Fire
Suppression Rating Schedule (FSRS), which is an analysis tool of the Public Protection Classification (PPC™) programme of the Insurance Service Office-USA (ISO).
This criteria produces an expected response time of 3,2 minutes for an engine company and 4,9 minutes for a ladder-service company, based on a formula developed by the New York City RAND Institute (USA).
RAND conducted extensive studies of fire department response times. They concluded that the average speed for a fire apparatus responding with emergency lights and siren is 35 mph (56.32kmh). This average speed considers average terrain, average traffic, weather and slowing down for intersections.
Taking into account the average speed and the time required for an apparatus to accelerate from a stop to the travel speed, RAND developed the following equation for calculating the travel time:
RAND conducted extensive studies of fire department response times. They concluded that the average speed for a fire apparatus responding with emergency lights and siren is 35 mph (56.32kmh). This average speed considers average terrain, average traffic, weather and slowing down for intersections.
Taking into account the average speed and the time required for an apparatus to accelerate from a stop to the travel speed, RAND developed the following equation for calculating the travel time:
Figure 3: RAND Institute equation for calculation of travel time
Calculations on SANS and NFPA methodologies
It is suggested (as essential) that when planning for optimal siting of future fire stations, that both the SANS and NFPA methodologies for calculation, where one is risk category-based and the other community centric, be utilised.
The results for optimal siting of fire station will then be based on variable ranges of risk, maximum required travel times, estimated speed of appliance, distance, resultant coverage areas that when inputted into the RAND equation, will provide resultant average travel time to actually cover the road kilometres.
The tables below show the calculations for the categories of fire risk based on maximum travel times, estimated speeds of appliance and actual time to cover the road kilometre distance.
Table 1: Fire response coverage for category A fire risks
Calculations on SANS and NFPA methodologies
It is suggested (as essential) that when planning for optimal siting of future fire stations, that both the SANS and NFPA methodologies for calculation, where one is risk category-based and the other community centric, be utilised.
The results for optimal siting of fire station will then be based on variable ranges of risk, maximum required travel times, estimated speed of appliance, distance, resultant coverage areas that when inputted into the RAND equation, will provide resultant average travel time to actually cover the road kilometres.
The tables below show the calculations for the categories of fire risk based on maximum travel times, estimated speeds of appliance and actual time to cover the road kilometre distance.
Table 1: Fire response coverage for category A fire risks
Table 2: Fire response coverage for category B fire risk
Table 3: Fire response coverage for category C fire risk
Table 4: Fire response coverage for category D fire risk
Changing the standard and the approach: a new criterion In reading the above tables and computing the averages (arithmetic mean) of categories A, B, and C fire risks (category D – rural risks deliberately excluded) and including the average of the travel time by road and average of square kilometres that can be covered against the preceding calculated averages, the following conclusion is then possible as a benchmark criterion for the planning and siting of fire stations for built upon areas in South Africa.
This above suggested benchmark criterion therefore takes into account the decentralisation of risk as influenced by the urban complexity factor and makes the intent of community protection against fire more plausible by focusing on a consistency of response travel requirement.
Using the new benchmark criterion for community-centric fire response (as concluded above) against the response time function of a fire station, the following verification of estimation is possible:
Where:
This above suggested benchmark criterion therefore takes into account the decentralisation of risk as influenced by the urban complexity factor and makes the intent of community protection against fire more plausible by focusing on a consistency of response travel requirement.
Using the new benchmark criterion for community-centric fire response (as concluded above) against the response time function of a fire station, the following verification of estimation is possible:
Where:
T= Response time of the fire station in minutes
t0 = Turnout time in minutes
K = Traffic impedance factor
r = Distance in kilometres
Thus to estimate the value of K, the formula would have to be substituted with the probable benchmark criteria of road kilometre travel radius (r) of four kilometres with an estimated turnout time (t0) of one minute and a response time of seven minutes; thus K would equal to 1,5.
Alternatively, by using the formula Τ=to + K(r) where K is known (as a result of detailed traffic studies) and where t_0 and r are the variables, it will then also be possible to embark on analysis of historical response data. This will aide in improving the management of turnout times taking into consideration the urban diversity and varying complexities of different parts of the areas to be protected.
Attendance time standard for community-centric fire response
As the travel time is a component of the response time sequence and travel can only occur after turnout and dispatch and dispatch can only occur after call taking, it is then possible derive the attendance time for a first arriving firefighting unit in a built-upon area.
This is done by adding the three minutes cumulative maximum time allocated for call taking, dispatch and turnout and adding this to the benchmark travel time criteria of seven minutes.
Thus the attendance time standard for community-centric fire response can be stated as: The total attendance time from time of call to time of arrival for a first arriving firefighting response apparatus should be 10 minutes or less for any structural fire incident in a built-upon area.
The response convergence principle
The influence of the urban complexity factor coupled with the additional pressures of continuing expansion of urban edges, increasing traffic densities and decentralisation of central business districts into integrated human settlements warrants (and desperately so) a new approach to the way we actually design fire stations.
The proposed attendance time standard for community-centric fire response also suggests the shift away from large centralised fire stations (one town-one fire station model) and instead decentralisation to real community focused (smaller) fire stations in built upon areas by virtue of promoting turnout overlaps where larger built-upon areas would have more than one fire station strategically located within the built upon area in order to meet the initial seven minute response travel time window.
Benchmark travel time criterion for community centric fire response
A community fire station should be located to provide fire protection for a built- upon area with an initial coverage span of 42km2 and a first due firefighting response unit travelling at an average speed of 37,5 km/h should take five minutes to cover four road kilometres and provide an expected initial response travel time of not more than seven minutes to a structural fire in that coverage area.
This will promote the concept of response convergence where stations could be located (in simple terms) within 14 minutes travel time from each other ie seven minutes to a central point and where mindful of potential traffic flow and other response barrier issues, firefighting (and other emergency response) resources could be decentralised to smaller stations thereby ensuring that at any given time there is a potential firefighting response apparatus and crew available to respond and converge upon the incident.
The automatic tracking of vehicles also is a factor that must be used to promote the shift away from standing response areas and where instead the mindset should be dispatch that which is closest in terms of road travel time.
Using GIS for travel time modelling
The use of geographic information systems (GIS) to perform response travel time modelling can easily incorporate other current and future development factors in order to determine more realistic travel time modelling.
The incorporation of aspects of current and future development, public transport and road network systems information in GIS travel time modelling will highlight areas that would be characterised by intensification of human and transport activity and also at the same time identify how these factors could potentially impact on traffic flows, which will assist in gauging how street attribute information will influence the expected response travel times from identified possible station locations so identified during the stages of location planning.
Added advantages of using GIS can be extended to historic analysis of fire response throughout the jurisdictional area, which will further influence future coverage decision making in terms of highlighting coverage gaps, response trends and patterns, fire and life safety risk indicators and turnout overlaps gaps in built upon areas and importantly the need to create future turnout overlaps as development occurs in the area and as suggested by the community-centric fire response criteria.
The next and final part of the series will focus on choosing a site and will detail site functionality and location.
t0 = Turnout time in minutes
K = Traffic impedance factor
r = Distance in kilometres
Thus to estimate the value of K, the formula would have to be substituted with the probable benchmark criteria of road kilometre travel radius (r) of four kilometres with an estimated turnout time (t0) of one minute and a response time of seven minutes; thus K would equal to 1,5.
Alternatively, by using the formula Τ=to + K(r) where K is known (as a result of detailed traffic studies) and where t_0 and r are the variables, it will then also be possible to embark on analysis of historical response data. This will aide in improving the management of turnout times taking into consideration the urban diversity and varying complexities of different parts of the areas to be protected.
Attendance time standard for community-centric fire response
As the travel time is a component of the response time sequence and travel can only occur after turnout and dispatch and dispatch can only occur after call taking, it is then possible derive the attendance time for a first arriving firefighting unit in a built-upon area.
This is done by adding the three minutes cumulative maximum time allocated for call taking, dispatch and turnout and adding this to the benchmark travel time criteria of seven minutes.
Thus the attendance time standard for community-centric fire response can be stated as: The total attendance time from time of call to time of arrival for a first arriving firefighting response apparatus should be 10 minutes or less for any structural fire incident in a built-upon area.
The response convergence principle
The influence of the urban complexity factor coupled with the additional pressures of continuing expansion of urban edges, increasing traffic densities and decentralisation of central business districts into integrated human settlements warrants (and desperately so) a new approach to the way we actually design fire stations.
The proposed attendance time standard for community-centric fire response also suggests the shift away from large centralised fire stations (one town-one fire station model) and instead decentralisation to real community focused (smaller) fire stations in built upon areas by virtue of promoting turnout overlaps where larger built-upon areas would have more than one fire station strategically located within the built upon area in order to meet the initial seven minute response travel time window.
Benchmark travel time criterion for community centric fire response
A community fire station should be located to provide fire protection for a built- upon area with an initial coverage span of 42km2 and a first due firefighting response unit travelling at an average speed of 37,5 km/h should take five minutes to cover four road kilometres and provide an expected initial response travel time of not more than seven minutes to a structural fire in that coverage area.
This will promote the concept of response convergence where stations could be located (in simple terms) within 14 minutes travel time from each other ie seven minutes to a central point and where mindful of potential traffic flow and other response barrier issues, firefighting (and other emergency response) resources could be decentralised to smaller stations thereby ensuring that at any given time there is a potential firefighting response apparatus and crew available to respond and converge upon the incident.
The automatic tracking of vehicles also is a factor that must be used to promote the shift away from standing response areas and where instead the mindset should be dispatch that which is closest in terms of road travel time.
Using GIS for travel time modelling
The use of geographic information systems (GIS) to perform response travel time modelling can easily incorporate other current and future development factors in order to determine more realistic travel time modelling.
The incorporation of aspects of current and future development, public transport and road network systems information in GIS travel time modelling will highlight areas that would be characterised by intensification of human and transport activity and also at the same time identify how these factors could potentially impact on traffic flows, which will assist in gauging how street attribute information will influence the expected response travel times from identified possible station locations so identified during the stages of location planning.
Added advantages of using GIS can be extended to historic analysis of fire response throughout the jurisdictional area, which will further influence future coverage decision making in terms of highlighting coverage gaps, response trends and patterns, fire and life safety risk indicators and turnout overlaps gaps in built upon areas and importantly the need to create future turnout overlaps as development occurs in the area and as suggested by the community-centric fire response criteria.
The next and final part of the series will focus on choosing a site and will detail site functionality and location.
