Method for traffic situation determination on the basis of reporting vehicle data for a traffic network with traffic-controlled network nodes

Claim 3

The method according to claim 1 , wherein the travel times (t tr (j,k) ) and the traffic situation parameter or parameters are determined specifically for each direction lane set (k) of the particular roadway section (j).

Claim 4

The method according to claim 1 , wherein the traffic situation parameter value or values obtained from the determined roadway-section specific travel times are used continuously for producing at least one of: historical progress lines relating to the mean number of vehicles in a particular queue; length of the particular queue; mean waiting time in the queue and/or the mean number of vehicles on the particular roadway section (j, k).

Claim 5

The method according to claim 1 , wherein turn-off rates are used as further traffic situation parameters obtained from determined roadway-section specific travel times, which turn-off rates in each case indicate a rate of vehicles which travel from an incoming direction lane set via a network node into an outgoing direction lane set.

Claim 6

The method according to claim 1 , wherein: a threshold value (t s (j,k) ) is predetermined in accordance with the relationship ( t S (j,k) )= L (j,k) /V free (j,k) ( p (j,k) )+β (j,k) ( T R (j,k) −γ (j,k) T G (j,k) T R (j,k) /T (j,k) ) for distinguishing between a subsaturated state on the one hand and a supersaturated state on the other hand; subsaturation of the particular roadway section (j, k) is deduced if the determined travel time (t tr (j,k) ) is less than the threshold value (ts (j,k) ); and supersaturation is deduced if the determined travel time is greater than the threshold value; with L (j,k) being the length of the roadway section (j, k); T R (j,k) being a traffic control interruption phase duration; T G (j,k) being a traffic control free phase duration; T (j,k) =T G (j,k) +T R (j,k) being a traffic control period duration; V free (j,k) (p (j,k) ) being a vehicle-density-dependent mean vehicle speed outside the queue; β (j,k) being a constant, which can be determined, that is greater than or equal to zero and less than one; γ (j,k) =q sat (j,k) b (j,k) /[n (j,k) V free (j,k) ( p (j,k) )]; q sat (j,k) being a queue saturation outlet flow of the particular roadway section (j, k); b (j,k) being a mean vehicle interval in the queue; and n (j,k) being a number of lanes.

Claim 7

The method according to claim 1 , wherein the roadway-section-specific vehicle situation parameters comprising the mean vehicle density (p (j,k) ) outside the queue, the mean number of vehicles (N (j,k) ), the mean number of vehicles in the queue (N q (j,k) ), queue length (L q (j,k) ) and waiting time (t q (j,k) ) in the queue for the subsaturated state are obtained by means of the following equation system: ρ ( j , k ) = N ( j , k ) - N q ( j , k ) n ( j , k )  ( L ( j , k ) - L q ( j , k ) ) N ( j , k ) = q sat ( j , k )  t tr ( j , k )  t tr ( j , k ) - [ L ( j , k ) / v free ( j , k )  ( ρ ( j , k ) ) ] - β ( j , k )  ( T R ( j , k ) ) 2 / T ( j , k ) t tr ( j , k ) - [ L ( j , k ) / v free ( j , k )  ( ρ ( j , k ) ) ] - γ ( j , k )  β ( j , k )  ( T R ( j , k ) ) 2 / T ( j , k ) N q ( j , k ) = q sat ( j , k )  [ t tr ( j , k ) - L ( j , k ) / v free ( j , k )  ( ρ ( j , k ) ) - β ( j , k )  ( T R ( j , k ) ) 2 / T ( j , k ) ] / ( 1 - γ ( j , k ) ) L q ( j , k ) = b ( j , k )  N q ( j , k ) / n ( j , k ) t q ( j , k ) = [ t tr ( j , k ) - L ( j , k ) / v free ( j , k )  ( ρ ( j , k ) ) - γ ( j , k )  β ( j , k )  ( T R ( j , k ) ) 2 / T ( j , k ) ] / ( 1 - γ ( j , k ) ) and for the supersaturated state are obtained by means of the following equation system: ρ ( j , k ) =  N ( j , k ) - N q ( j , k ) n ( j , k )  ( L ( j , k ) - L q ( j , k ) ) N ( j , k ) =  t tr ( j , k )  q sat ( j , k )  T G ( j , k ) / T ( j , k ) N q ( j , k ) =  q sat ( j , k )  T G ( j , k )  [ t tr ( j , k ) - L ( j , k ) / v free ( j , k )  ( ρ ( j , k ) ) ] / [ ( 1 - γ t ( j , k ) )  T ( j , k ) ] L q ( j , k ) =  b ( j , k )  N q ( j , k ) / n ( j , k ) t q ( j , k ) =  N q ( j , k )  T ( j , k ) / ( T G ( j , k )  q sat ( j , k ) ) , where γ (j,k) =q sat (j,k) b (j,k) /[n (j,k) V free (j,k) ( p (j,k) )]; γ 1 (j,k) =γ (j,k) T G (j,k) /T (j, k) ; in each case specifically for a particular direction lane set k of a particular roadway section j; L is the total roadway length; T R is the duration of the interruption or red phases; T G is the duration of the free or green phases; T=T G +T R is an associated traffic control period duration; q sat is a predetermined saturation outlet flow from the queue; b is a mean vehicle interval in queues; n is a number of lanes; v free is the mean vehicle speed, dependent on the vehicle density outside the queue; and β is a suitably predetermined constant.

Claim 8

The method according to claim 1 , wherein: traffic situation parameters comprising the mean number of vehicles (N (j,k) ), effective continuous roadway section inlet flow (q in (j,k) ) and effective continuous queue inlet flow (q in/q (j,k) ) are obtained from traffic data from at least two reporting vehicles which are traveling at a time interval (Δt (j,k) ) greater than or equal to a traffic control period duration (T (j,k) ) on the same roadway section (j, k), using the difference (Δt tr (j,k) ) between determined travel times of the reporting vehicles; and the relationship; q in (j,k) =(1 +Δt tr (j,k) /Δt (j, k) ) qsat (j,k) T G (j,k) /T (j,k) and the approximation Δ t free (j,k) <<Δt (j,k) are in this case used to determine an effective continuous roadway section inlet flow (q in (j,k) ), t free being a travel time difference from the roadway section start to the queue start.

Claim 9

The method according to claim 1 , wherein: an overfull roadway section is deduced if a reporting vehicle is located on the relevant roadway section (j, k) for a time period greater than a critical travel time (t tr,crit (j,k) ), being a determined travel time that satisfies an implied relationship b (j,k) N q (j,k) /n (j,k) =L (j,k) where the mean number of vehicles in the queue (N q (j,k) ) is that for a supersaturated case.

Claim 10

The method according to claim 1 , wherein sources and sinks of vehicle flow on the traffic network are taken into account in determining traffic situation parameters by means of corresponding inlet flows ( Tq (j,k) ) and outlet flows ( Ts (j,k) ) to and from the particular roadway section (j, k).

Claim 11

The method according to claim 9 , wherein: the traffic network which is considered for determining the traffic situation comprises only a predeterminable portion of all roadway sections and network nodes in an overall traffic network; and roadway sections and network nodes that are not considered in this case are regarded as sources and sinks of vehicle flow on the traffic network under consideration.