CN102542811A - Method for determining step-by-step speed limit value of exit ramp of freeway - Google Patents

Abstract

The invention relates to a method for determining a step-by-step speed limit value of an exit ramp of a freeway, belonging to the field of traffic operation management of the freeway. The method comprises the following steps: dividing a speed characteristic value of the exit ramp into three site vehicle speeds, including a ramp nose end part, a transition section starting point and a reasonable outer side mainline of an exit ramp upstream section, through a research on running vehicle speed and deceleration of the exit ramp upstream section; deducing a running speed of the transition section starting point according to a ramp nose end speed limit value, continuously deducing a vehicle speed of the reasonable outer side mainline lane, combining an investigated or predicted mainline vehicle running speed to acquire a speed limit value calculation model and a corresponding calculation formula, finally determining a final step-by-step speed limit value according to engineering experience. Based on verification results of the method disclosed by the invention in combination with examples, the method disclosed by the invention has the advantages of simple and convenient calculation, high precision, suitability for engineering practical application and the like, effectively solves the shortcomings of the prior art and can be widely applied to the traffic operation management of the freeway.

Description

A kind of expressway exit ring road is definite method of speed limit step by step

Technical field

The present invention relates to a kind of expressway exit ring road definite method of speed limit step by step, belong to freeway traffic operation management field.

Background technology

Expressway exit ring road Upstream section speed limit step by step is meant in the exit ramp scope vehicle is carried out the two-stage Control for Speed Limitation.Wherein, main line outside speed limit in advance is the first order, and ring road nose speed limit is the second level.Find that after deliberation vehicle is under the condition that ring road nose single-stage speed limit is only arranged, travel speed is difficult for falling, and vehicle sails the exit ramp excessive velocities into, causes traffic hazard easily.Therefore, through Control for Speed Limitation in advance, guarantee that vehicle sails exit ramp into the speed of a motor vehicle that meets the requirement of exit ramp speed limit to the main line kerb lane.

At present, design relevant codes and standards according to the highway engineering of China, unique foundation that highway is provided with speed limit is a design rate, and national highway is all with the value foundation of design rate as speed(-)limit sign.But both at home and abroad the expert generally believes that to carry out speed limit according to design rate too conservative.In recent years, domestic research about speed limit is more, mainly can be divided into following two types:

(1) Control for Speed Limitation of studying to the driver

The research of this type is mainly studied from driver's reaction velocity, behavioural characteristic.More representative treatise has:

Luo Liangxin etc. start with from driver's the rate of information throughput, and the speed limit computing formula of the ergonomic of having derived is for the setting of road traffic system reasonable limits speed provides new thinking.

Open slowly etc. the driver is studied in the road Che Shiqi speed selection problem that speed limit is arranged, drawn statistics conclusion with certain significance.

Pei Jiantao etc. are that index is analyzed driver's the age and the speed of a motor vehicle with reaction time, actuation time and brake reaction time, and having drawn the speed of a motor vehicle is the conclusion that influences the remarkable factor of driver's reaction.

(2) consider the Control for Speed Limitation that traffic environment is studied

The research of this type is mainly logical to be studied the multiplicity that carries out of road environment.More representative treatise has:

In violation of rules and regulations ratio of slip, road vehicle classification and proportion thereof, the driver that the theory that Wu Jingmei proposes need be taken all factors into consideration road accident quantity, the possibility of enforcement, the factors such as expense of compulsory execution are come V ₈₅Speed limit is revised.

Sun Huiyuan, Sun Li etc. are inquiring on the basis that concerns between newly-built highway restricted speed and the traffic safety sighting distance value; Traffic safety sighting distance value and influence factor that newly-built highway restricted speed is adopted quantize the traffic safety horizon range that provides newly-built highway speed limit to select for use.

Abroad the research direction for Control for Speed Limitation mainly contains two:

(1) travelling speed statistical study

In the related specifications abroad, confirming of speed limit mainly is 85% speed V according to the observation travelling speed ₈₅This result is that the American Studies personnel draw through after the observation and statistic.They find that the speed of a motor vehicle (more than 70%) of the overwhelming majority is distributed near the scope of 10 miles per hours (16km/h) of average speed its higher limit and V ₈₅Approximately equal is in order to control the discreteness of the speed of a motor vehicle, with V ₈₅As standard of the limited speed.This simultaneously also all receives the influence of " the U-shaped curve of accident and velocity contrast " of Solomon relevant with European and American countries.1964; Solomon passes through on the 970km highway section; 10000 drivers relevant with accident investigate discovery; The accident number becomes the U-shaped curved line relation with

, and nineteen ninety Harkey, people's such as Fildes in 1991 research also has same conclusion.When going, low accident rate is arranged with the speed of a motor vehicle in standard deviation velocity range of average velocity; The position was (near V near average velocity added 10km/h ₈₅Speed), accident rate is minimum.In MUCTD, spell out, speed limit should be at free flow speed V ₈₅± 10km/h or V ₈₅In the scope of ± 5mph.Britain, Australia are similar with the U.S. with Canadian speed limit principle, at V ₈₅Take all factors into consideration road conditions, the suitable reduction of historical casualty data on the basis of speed.The advantage of this speed-limiting control method is that engineering is used simply, the coincidence statistics rule, and its is fit to the Control for Speed Limitation of highway section stabilizing speed, but at two kinds of means of transportation joining places that the design rate difference is bigger, the speed of a motor vehicle itself is just changing, and adopts single V this moment ₈₅Speed limit does not also meet the actual change rule of the speed of a motor vehicle.

(2) comprehensive traffic factor analysis

New Zealand adopts and according to factors such as road conditions, surrounding enviroment, the volume of traffic road is divided into some safe classes as the speed limit foundation; And formulated detailed process flow diagram; Its speed limit scope be 20km/h to 100km/h, high value is the Control Speed Limitation on Freeway value.This method for limiting speed has synthetically been considered the various factors of traffic environment, but does not include the regularity of distribution of the speed of a motor vehicle in flow process.

Australia road research committee (ARRB) has developed road safety application software---XLIMITES; This software comprises complicated decision support method, software consideration influence factors such as existing vehicle-speed limit, soil utilization, roadway characteristic, historical accident confirm new vehicle-speed limit recommendation.

Be not difficult to find out from above background technology; Adopt different angles that the reasonable Control for Speed Limitation mode of highway is studied both at home and abroad; But the survey region of these two class methods is the highway main line, the car speed and the retarded velocity characteristic in exit ramp zone is not made analysis.In engineering practice, definite process of the speed limit of ring road and main line is the foundation of lack of scientific often, exists potential safety hazard.

The mentioned speed limit of the present invention confirms that methodological principle is human oriented design.This method research is under the prerequisite that meets the existing driving behavior custom of driver, to carry out, and is guidance with the retarded velocity regularity of distribution of field investigation, calculates reasonably Control for Speed Limitation value step by step.Therefore, method of the present invention be exit ramp step by step speed limit theoretical foundation is provided, reduce traffic safety hidden danger, improve travel safety.

Summary of the invention

The present invention provides a kind of expressway exit ring road that more meets the actual travel situation definite method of speed limit step by step.

The technical scheme that the present invention adopts is:

1) according to the ring road speed limit V at exit ramp nose place _G0With the deceleratuib lane mid point to the nose place available vehicel deceleration a ₀₁, the suitable speed V of calculating deceleratuib lane mid point section _t', its computing formula is:

$V_t^{\′}=3.6\×\sqrt{a_{01}d+{(V_{g0}/3.6)}^2}---\left(1\right)$

D is the deceleratuib lane length that contains transition, m;

2) by the suitable speed V of deceleratuib lane mid point section _t' and transition starting point to deceleratuib lane mid point section part available vehicel deceleration a ₀₂, the suitable speed V at calculating transition starting point place _t, its computing formula is:

$V_t=3.6\×\sqrt{a_{02}d+{(V_t^{\′}/3.6)}^2}---\left(2\right)$

Merge (1) formula and (2) Shi Kede:

$V_t=3.6\×\sqrt{(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(3\right)$

3) 500 meters, the upper reaches with exit ramp transition starting point are the starting point that the kerb lane vehicle gets into the exit ramp zone, by the suitable speed V at exit ramp transition starting point place _tAnd 500 meters section (L of exit ramp transition starting point Upstream section ₁) available vehicel deceleration a _t, calculate the reasonable computation initial velocity V that the kerb lane vehicle gets into the exit ramp zone _T, its computing formula is:

$V_T=3.6\×\sqrt{{2a}_t{L}_1+{\left(\frac{V_t}{3.6}\right)}^2}=3.6\×\sqrt{{2a}_t{L}_1+(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(4\right)$

4) get into the regional reasonable computation initial velocity V of exit ramp by the kerb lane vehicle _TAnd exit ramp upper reaches kerb lane Vehicle Speed V ₀, calculate main line kerb lane speed limit calculated value V step by step _g', its computing formula is:

${V_g}^{\′}=V_0\sqrt{\frac{0.903-\ln (\frac{V_0}{V_T}-1)}{3.650}}---\left(5\right)$

Formula (1) is to formula (5):

V _G0-exit ramp nose speed limit, km/h;

V _t'-deceleratuib lane mid point section calculates suitable speed, km/h;

V _t-deceleratuib lane transition starting point section kerb lane calculates suitable speed, km/h;

V _T-kerb lane vehicle gets into the reasonable computation initial velocity in exit ramp zone, km/h;

V ₀-exit ramp upper reaches kerb lane Vehicle Speed, km/h;

V _g'-main line kerb lane is the speed limit calculated value step by step, km/h;

a ₀₁-deceleratuib lane mid point to nose place available vehicel deceleration, m/s ²

a ₀₂-transition starting point to deceleratuib lane midpoint available vehicel deceleration, m/s ²

a _t-exit ramp transition starting point Upstream section available vehicel deceleration, m/s ²

D-contains the deceleratuib lane length of transition, m;

L ₁-exit ramp zone transition starting point Upstream section length, L ₁=500m;

5) the main line kerb lane calculates reasonable speed limit V _g' round downwards by 10, and be final speed limit V with the value after rounding _g

The ring road speed limit V at formula (1) middle outlet ring road nose place _G0Be 40km/h or 60km/h.

Formula (4) middle outlet ring road transition starting point 500 meters section (L in the upper reaches ₁) available vehicel deceleration a _tValue is 0.15m/s ²When deceleratuib lane during less than 200m, the deceleratuib lane mid point is available vehicel deceleration a to the nose place ₀₁Value is 0.73m/s ², transition starting point to deceleratuib lane midpoint available vehicel deceleration a ₀₂Value is 1.30m/s ²When deceleratuib lane during greater than 200m, a ₀₁Value is 1.09m/s ², a ₀₂Value is 0.31m/s ²

Compared with prior art, the present invention has following characteristics: the present invention system first proposes expressway exit ring road zone speed limit computing method step by step.The present invention is divided into three zones with the exit ramp Upstream section, has confirmed each regional different deceleration value, more meets driver's behavioural characteristic; From driver's angle, expressway exit ring road that a cover meets driving behavior custom speed limit computing formula has step by step been proposed.It is scientific and reasonable that the present invention can guarantee that expressway exit ring road zone speed limit is confirmed, avoided the artificial subjective errors of confirming that speed limit is caused.

Description of drawings

Fig. 1 is the calculation flow chart of speed limit step by step.

Fig. 2 is an exit ramp zone segmentation synoptic diagram.

Fig. 3 is a high speed exit ramp instance graph.

Embodiment

The technical scheme that the present invention adopts is:

1) according to the ring road speed limit V at exit ramp nose place _G0With the deceleratuib lane mid point to the nose place available vehicel deceleration a ₀₁, the suitable speed V of calculating deceleratuib lane mid point section _t', its computing formula is:

$V_t^{\′}=3.6\×\sqrt{a_{01}d+{(V_{g0}/3.6)}^2}---\left(1\right)$

D is the deceleratuib lane length that contains transition, m;

2) by the suitable speed V of deceleratuib lane mid point section _t' and transition starting point to deceleratuib lane mid point section part available vehicel deceleration a ₀₂, the suitable speed V at calculating transition starting point place _t, its computing formula is:

$V_t=3.6\×\sqrt{a_{02}d+{(V_t^{\′}/3.6)}^2}---\left(2\right)$

Merge (1) formula and (2) Shi Kede:

$V_t=3.6\×\sqrt{(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(3\right)$

3) 500 meters, the upper reaches with exit ramp transition starting point are the starting point that the kerb lane vehicle gets into the exit ramp zone, by the suitable speed V at exit ramp transition starting point place _tAnd 500 meters section (L of exit ramp transition starting point Upstream section ₁) available vehicel deceleration a _t, calculate the reasonable computation initial velocity V that the kerb lane vehicle gets into the exit ramp zone _T, its computing formula is:

$V_T=3.6\×\sqrt{{2a}_t{L}_1+{\left(\frac{V_t}{3.6}\right)}^2}=3.6\×\sqrt{{2a}_t{L}_1+(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(4\right)$

4) get into the regional reasonable computation initial velocity V of exit ramp by the kerb lane vehicle _TAnd exit ramp upper reaches kerb lane Vehicle Speed V ₀, calculate main line kerb lane speed limit calculated value V step by step _g', its computing formula is:

${V_g}^{\′}=V_0\sqrt{\frac{0.903-\ln (\frac{V_0}{V_T}-1)}{3.650}}---\left(5\right)$

Formula (1) is to formula (5):

V _G0-exit ramp nose speed limit, km/h;

V _t'-deceleratuib lane mid point section calculates suitable speed, km/h;

V _t-deceleratuib lane transition starting point section kerb lane calculates suitable speed, km/h;

V _T-kerb lane vehicle gets into the reasonable computation initial velocity in exit ramp zone, km/h;

V ₀-exit ramp upper reaches kerb lane Vehicle Speed, km/h;

V _g'-main line kerb lane is the speed limit calculated value step by step, km/h;

a ₀₁-deceleratuib lane mid point to nose place available vehicel deceleration, m/s ²

a ₀₂-transition starting point to deceleratuib lane midpoint available vehicel deceleration, m/s ²

a _t-exit ramp transition starting point Upstream section available vehicel deceleration, m/s ²

D-contains the deceleratuib lane length of transition, m;

L ₁-exit ramp zone transition starting point Upstream section length, L ₁=500m;

5) the main line kerb lane calculates reasonable speed limit V _g' round downwards by 10, and be final speed limit V with the value after rounding _g

The ring road speed limit V at formula (1) middle outlet ring road nose place _G0Be 40km/h or 60km/h.

Formula (4) middle outlet ring road transition starting point 500 meters section (L in the upper reaches ₁) available vehicel deceleration a _tValue is 0.15m/s ²When deceleratuib lane during less than 200m, the deceleratuib lane mid point is available vehicel deceleration a to the nose place ₀₁Value is 0.73m/s ², transition starting point to deceleratuib lane midpoint available vehicel deceleration a ₀₂Value is 1.30m/s ²When deceleratuib lane during greater than 200m, a ₀₁Value is 1.09m/s ², a ₀₂Value is 0.31m/s ²

The purpose of this invention is to provide-kind of expressway exit ring road definite method of speed limit step by step, typical expressway exit ring road synoptic diagram is as shown in Figure 2, and the exit ramp zone is divided into L ₁, L ₂, L ₃Three sections, wherein, L ₁Be meant transition starting point Upstream section length, value is 500 meters among the present invention; L ₂, L ₃The common deceleratuib lane length that contains transition, the L of forming ₂With L ₃Intersection is the deceleratuib lane midpoint.Through each section velocity contrast variation tendency discovered L among Fig. 2 ₁The section changes in vehicle speed is mild, can suppose should the zone in vehicle do uniformly retarded motion; And on deceleratuib lane, L ₂With L ₃The section car speed differs greatly, and needs research respectively, but vehicle still is regarded as doing uniformly retarded motion on each section.Vehicle arrives L ₃The section end, i.e. ring road nose place, the speed of a motor vehicle has been reduced to the ring road speed limit and has been got into ring road and go.

Specific embodiments is as shown in Figure 3, uses step by step the speed limit computing method and confirms final speed limit.The high speed main line is two-way 6 tracks, and the main line speed limit is 120km/h, and exit ramp is unidirectional two tracks, and the ring road speed limit is 40km/h, i.e. V _G0=40km/h; The deceleratuib lane length that contains transition is 170 meters, i.e. d=170 rice.L ₃Section average retardation rate a ₀₁Value is 0.73m/s ², L ₂Section average retardation rate a ₀₂Value is 1.3m/s ², L ₁Section average retardation rate a _tValue is 0.15m/s ²This outlet Upstream section kerb lane vehicle ' average speed is 98km/h, i.e. V ₀=98km/h.Can calculate this exit ramp speed limit calculated value step by step by above data, its step is following:

1) suitable speed of calculating deceleratuib lane mid point section.According to V _G0=40km/h, d=170m and a ₀₁=0.73m/s ², utilize formula (1) to get the suitable speed V of deceleratuib lane mid point section _t':

$V_t^{\′}=3.6\×\sqrt{a_{01}d+{(V_{g0}/3.6)}^2}=3.6\×\sqrt{0.73\×170+{(40/3.6)}^2}=56.6\mathrm{km}/h$

2) suitable speed at calculating transition starting point place.According to V _t'=56.6km/h, d=170m and a ₀₂=1.3m/s ², utilize formula (2) to get the suitable speed V at transition starting point place _t:

$V_t=3.6\×\sqrt{a_{02}d+{(V_t^{\′}/3.6)}^2}=3.6\×\sqrt{1.3\×170+{(56.6/3.6)}^2}=77.9\mathrm{km}/h$

3) calculate the reasonable computation initial velocity that the kerb lane vehicle gets into the exit ramp zone.According to V _t=77.9km/h, d=170m, L ₁=500m and a _t=0.15m/s ², utilize formula (4) to get the reasonable computation initial velocity V that the kerb lane vehicle gets into the exit ramp zone _T:

$V_T=3.6\×\sqrt{{2a}_t{L}_1+{\left(\frac{V_t}{3.6}\right)}^2}=3.6\×\sqrt{2\×0.15\×500+{(77.9/3.6)}^2}=89.5\mathrm{km}/h$

4) calculate main line kerb lane speed limit calculated value step by step.According to V _T=89.5km/h and V ₀=98km/h utilizes formula (5) to get main line kerb lane speed limit calculated value V step by step _g':

$V_g^{\′}=V_0\sqrt{\frac{0.903-\ln (\frac{V_0}{V_T}-1)}{3.650}}=98\×\sqrt{\frac{0.903-\ln (\frac{98}{89.5}-1)}{3.650}}=92.6\mathrm{km}/h$

5) round downwards by 10 calculating speed limit, obtain final speed limit V _g=90km/h.

Claims (3)

1. an expressway exit ring road definite method of speed limit step by step is characterized in that, comprises the steps:

1) according to the ring road speed limit V at exit ramp nose place _G0With the deceleratuib lane mid point to the nose place available vehicel deceleration a ₀₁, the suitable speed V of calculating deceleratuib lane mid point section _t', its computing formula is:

$V_t^{\′}=3.6\×\sqrt{a_{01}d+{(V_{g0}/3.6)}^2}---\left(1\right)$

D is the deceleratuib lane length that contains transition, m;

2) by the suitable speed V of deceleratuib lane mid point section _t' and transition starting point to deceleratuib lane mid point section part available vehicel deceleration a ₀₂, the suitable speed V at calculating transition starting point place _t, its computing formula is:

$V_t=3.6\×\sqrt{a_{02}d+{(V_t^{\′}/3.6)}^2}---\left(2\right)$

Merge (1) formula and (2) Shi Kede:

$V_t=3.6\×\sqrt{(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(3\right)$

3) 500 meters, the upper reaches with exit ramp transition starting point are the starting point that the kerb lane vehicle gets into the exit ramp zone, by the suitable speed V at exit ramp transition starting point place _tAnd 500 meters section (L of exit ramp transition starting point Upstream section ₁) available vehicel deceleration a _t, calculate the reasonable computation initial velocity V that the kerb lane vehicle gets into the exit ramp zone _T, its computing formula is:

$V_T=3.6\×\sqrt{{2a}_t{L}_1+{\left(\frac{V_t}{3.6}\right)}^2}=3.6\×\sqrt{{2a}_t{L}_1+(a_{01}+a_{02})d+{(V_{g0}/3.6)}^2}---\left(4\right)$

4) get into the regional reasonable computation initial velocity V of exit ramp by the kerb lane vehicle _TAnd exit ramp upper reaches kerb lane Vehicle Speed V ₀, calculate main line kerb lane speed limit calculated value V step by step _g', its computing formula is:

${V_g}^{\′}=V_0\sqrt{\frac{0.903-\ln (\frac{V_0}{V_T}-1)}{3.650}}---\left(5\right)$

Formula (1) is to formula (5):

V _G0-exit ramp nose speed limit, km/h;

V _t'-deceleratuib lane mid point section calculates suitable speed, km/h;

V _t-deceleratuib lane transition starting point section kerb lane calculates suitable speed, km/h;

V _T-kerb lane vehicle gets into the reasonable computation initial velocity in exit ramp zone, km/h;

V ₀-exit ramp upper reaches kerb lane Vehicle Speed, km/h;

V _g'-main line kerb lane is the speed limit calculated value step by step, km/h;

a ₀₁-deceleratuib lane mid point to nose place available vehicel deceleration, m/s ²

a ₀₂-transition starting point to deceleratuib lane midpoint available vehicel deceleration, m/s ²

a _t-exit ramp transition starting point Upstream section available vehicel deceleration, m/s ²

D-contains the deceleratuib lane length of transition, m;

L ₁-exit ramp zone transition starting point Upstream section length, L ₁=500m;

5) the main line kerb lane calculates reasonable speed limit V _g' round downwards by 10, and be final speed limit V with the value after rounding _g

2. a kind of expressway exit ring road according to claim 1 is definite method of speed limit step by step, it is characterized in that: the ring road speed limit V at said formula (1) middle outlet ring road nose place _G0Be 40km/h or 60km/h;

3. a kind of expressway exit ring road according to claim 1 is definite method of speed limit step by step, it is characterized in that: said formula (4) middle outlet ring road transition starting point 500 meters section (L in the upper reaches ₁) available vehicel deceleration a _tValue is 0.15m/s ²When deceleratuib lane during less than 200m, the deceleratuib lane mid point is available vehicel deceleration a to the nose place ₀₁Value is 0.73m/s ², transition starting point to deceleratuib lane midpoint available vehicel deceleration a ₀₂Value is 1.30m/s ²When deceleratuib lane during greater than 200m, a ₀₁Value is 1.09m/s ², a ₀₂Value is 0.31m/s ²

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