Segregation of
traffic on the movement area
4.1 need for traffic segregation
4.1.1 The potential for aircraft and ground vehicle
interactions exists on the runways, taxiways and aprons that make up the
aircraft movement area. The number of interactions can be minimized, however,
in the planning phase of the aerodrome facility by segregating the air and
ground traffic. Properly segregated traffic will minimize the possibility of
aircraft and ground vehicle collisions and maximize the efficiency of aircraft
movements. Those interactions that are necessary should be planned for predominated
areas using established procedures.
4.1.2 There is a need for some ground vehicles to
operate on the movement area for the purposes of aircraft servicing, aerodrome
maintenance and construction work, and emergency operations. However, because
of the different physical characteristics of aerodromes, no specific design
criteria can be established to promote segregation of traffic. There are,
however, a number of measures that may be taken to lessen the amount of mixing
of aircraft and ground vehicles.
4.2 Activities Causing A Mix Of Aircraft And Ground
Vehicles
4.2.1 The majority of interactions that can occur
between aircraft and ground vehicles take place on apron areas. The following
are some aircraft servicing operations performed on aprons that may involve
attendance of ground vehicles and that should be taken into account when
planning segregation of traffic on aprons:
(a) passenger unloading/loading;
(b) baggage unloading/loading;
(c) cargo and/or mail unloading/loading;
(d) galley service;
(e) sanitation service;
(f) fuelling service;
(g) provision of compressed air for engine starting;
(h) aircraft maintenance; and
(i)electric power and air conditioning (if not
provided by aircraft auxiliary power units).
In addition, provision should be made for emergency
and security vehicles on the apron areas.
4.2.2 Ground vehicle activities that occur on movement
areas outside of the aprons include the following:
(a) Emergency operations. Rescue and fire fighting
equipment, which may be required at any point on the aerodrome or runway
approach areas.
(b) Security operations. Small vehicles used for the
patrol of fence lines and restricted areas.
(c) Aerodrome maintenance and construction.
Repair of pavements, navigation aids and lighting,
grass mowing, snow/ice removal operations, etc.
4.3 Methods to Achieve Segregation
4.3.1 Several general concepts for achieving segregation
of traffic are presented in the following paragraphs. For apron areas in
particular, the degree of segregation which can be achieved depends largely on
the available space. The greater the amount of space available for a given
number of aircraft stands, the easier it is to segregate types of traffic.
Normally, the need for economy is such that aprons are rarely designed with
excess area and, in any case, air traffic growth generally absorbs any designed
spare apron area. The degree of segregation necessary is dependent on the
dimensions and other characteristics of aircraft (e.g. wing span,
manoeuvrability and jet blast) and the nature of the ground vehicles. In
addition, when planning an aerodrome, aircraft operators should be consulted to
determine their anticipated ground vehicle movement requirements.
Exclusion
4.3.2 Although the design of aerodrome facilities can
ease considerably the problem of mixing of aircraft with ground vehicles, it is
nevertheless most important that aircraft operators be conscious of the need to
keep the volume of their ground traffic to a minimum. All ground vehicles whose
function does not require them to be on the movement area should be excluded.
This practice is also in accord with basic aerodrome security measures. Land
side road systems should be designed so that public vehicles have access to all
public areas of an aerodrome without travelling on the movement area. Measures
should also be taken to prevent unauthorized access of public vehicles to the
movement area. This requires the provision of fences, gates and other security
systems needed to strictly control access.
Service roads for ground vehicles
4.3.3 Air side service roads for ground vehicles can
eliminate or lessen to a great extent the necessity for the use of runways and
taxiways by ground vehicles. Such roads should be planned so that at least the
critical sections of the movement area for traffic congestion can be bypassed
by ground vehicular traffic. For example, these roads may be used as aerodrome
perimeter service roads providing access to navigation aids, as temporary roads
for construction vehicles or as air side roads between terminal buildings and
aprons for the passage of airline vehicles, baggage trains, etc. For terminals
with passenger loading bridges, air side roads may (for some designs) pass
beneath the immovable part of the loading bridge. Figure 4‑1 shows
examples of air side service roads used on aprons. Some general considerations
in the planning of roads are described as follows:
(a) every effort should be made to plan air side service roads so that
they do not cross runways and taxiways. At high traffic aerodromes, road
tunnels beneath runways and taxiways should be considered at major
intersections in order to avoid such crossings;
(b) when planning the aerodrome road layout, account should be taken of
the need to provide emergency access roads for use by rescue and fire fighting
vehicles to various areas on the aerodrome and in particular to the approach
areas up to
(c) service roads to navigation aids should be planned in such a manner
as to present minimal interference to the function of the aids. If it is
necessary for an access road to cross an approach area, the road should be
located so that vehicles travelling on them are not obstacles to aircraft
operations; and
(d) the air side service road system must be designed to account for
local security measures. Access points to the system will thus need to be
restricted. Should ground vehicle movements affect surface movement of aircraft
on runways and taxiways, it will be required that the ground vehicle movements
be co‑ordinated by the appropriate aerodrome control. Control is normally
exercised by means of two‑way radio communication, although visual
signals, such as signal lamps, are adequate when the traffic at the aerodrome
is light. Signs or signals may also be employed to aid control at
intersections.
Fixed servicing installations
4.3.4 Many
apron service vehicles can be eliminated with the provision of fixed servicing
installations set either within the apron or within the terminal buildings
adjacent to the aircraft stands. For example, the provision of hydrant fuelling
systems, compressed air outlets, static power supplies, drainage outlets,
drinking water hydrants, air conditioning outlets and telephone outlets close
to aircraft stands would considerably reduce the equipment and vehicles
required for aircraft servicing. Loading bridges for passenger loading and
unloading can also be thought of as a form of fixed servicing installation as
they eliminate the need for passenger loading equipment and the need for
passengers to travel over the apron (either by walking or in a passenger
transport vehicle). Furthermore, loading bridges generally lend themselves to the
provision of fixtures for aircraft servicing operations. Some of the
disadvantages of fixed servicing installations are high initial costs and
limited flexibility for different aircraft types. However, if in the planning
stage careful consideration is given to the location and number of these
facilities, the required flexibility can be achieved. In addition, the
different power supply requirements of present‑day aircraft complicate
the provision of static power supplies; however, the trend in aircraft design
is towards greater standardization of electrical requirements. See the Airport
Planning Manual (Doc 9184), for planning considerations regarding fixed
servicing installations.
Markings
4.3.5 Paint
markings should be used to facilitate the segregation of traffic on aprons.
Markings can be used to provide guidance to pilots in manoeuvring their
aircraft safely and expeditiously on aprons. Other markings are used to
designate safety limits for placement of equipment on aprons, e.g. wing tip
clearance lines and other markings used to delineate access routes for ground
vehicles, passengers or personnel across the apron. There should be a colour
change between lines to distinguish one from another.
