Lane Combination Research Articles

Optimal control method of freeway based on tollbooths lane configuration and variable speed limit control

There are tollbooths on some freeway ramps, and toll lanes can be divided into Electronic Toll Collection (ETC), Manual Toll Collection system (MTC), ETC/MTC hybrid toll lanes and closed. The traffic capacity of different lanes is different. Different lane combinations are set to adjust the traffic flow of the ramp into the main line. Therefore, this strategy can be regarded as a kind of ramp metering (RM). This paper presents an optimal control method for freeways based on tollbooths lanes configuration and variable speed limit (VSL) control. Firstly, cellular automata model and cell transmission model are used to describe the operation of toll plazas and main line traffic flow respectively. Furthermore, the freeway control methods are constructed by using tollbooths RM (TB-RM) and TB-RM combined with main line VSL control respectively to improve the freeway traffic operation efficiency. Finally, the proposed method is simulated experimentally. Results from simulation experiments demonstrate that the proposed method (i) significantly improves the traffic performance in terms of total time spent savings; (ii) observably enhances driving safety.

OPTIMAL LINEAR COMBINATIONS SELECTION BASED ON FUZZY CLUSTERING ANALYSIS FOR MULTI-FREQUENCY GNSS

Abstract. Currently, satellite navigation and positioning systems, such as BDS, GPS, and Galileo, can broadcast 3 or more navigation signals. In theory, multi-frequency signals can form more high-quality carrier-phase linear combinations, which is conducive to improving the performance of multi-frequency carrier ambiguity resolution (MCAR). In this paper, focusing on the selection of the optimal combinations in the multi-frequency GNSS carrier phase ambiguity resolution, according to the long wavelength of the combinations, the influence of weak ionospheric delay, and low noise, the fuzzy clustering analysis method is used to realize objective selection of multi-frequency optimal linear combinations (e.g., GPS, BDS-2, BDS-3, Galileo) and introduced the total noise level (TNL) for the analysis of the combinations characteristics under different baseline length scenarios. In order to verify the ambiguity resolution performance of the extra-wide lane combinations selected by the fuzzy clustering analysis method, the GF_MCAR model was used to solve the BDS-2, BDS-3 triple-frequency combination ambiguities and the BDS-3 five-frequency combination ambiguities of the baseline JNFG and WUH2. The results manifest that the number of high-quality linear combinations of multi-frequency GNSS increases sharply with the increase of the frequencies number, which is conducive to the formation of combinations with a lower total noise level, and the experiments show that the difference between adjacent epochs of the combination ambiguities of the extra-wide lane obtained by GF_MCAR is basically less than ±0.5 cycles, and the single epoch rounding can be used to directly fix the ambiguity of the extra-wide lane.

An Optima Combination Method of Three-Frequency Real-Time Cycle Slip Detection for Non-Normal Ionospheric Variation Data

Linear combinations of triple-frequency help improve the performance of cycle slip detection for high-precision positioning using a single receiver; however, the position can be easily misjudged under ionospheric scintillation conditions or low sampling rates. We propose a method, which is developed specially for the datasets under ionospheric scintillation conditions or low sampling rates, to detect the triple-frequency cycle slips in real-time based on optimal linear combination coefficients and ionospheric range delay. Detection formulas are derived from the triple-frequency geometry-free code-phase combination, and ionospheric range delay is estimated by the wide lane combination. In addition, the principle used to select an optimal linear phase combination coefficient is derived, and the optimal linear coefficient suitable under high ionospheric activity conditions is provided. Finally, the data collected from self-build stations JYPS and NQ01 are used to test the performance of the method. The results demonstrate that the improved method can be used to detect all combinations of cycle slips in real-time, even under conditions of ionospheric scintillation or a sampling period exceeding 10 s.

Dynamic Allocation Model for Reversible Lanes in the Intelligent Vehicle Infrastructure Cooperative System

The real-time dynamic control of reversible lanes is an effective measure to alleviate the traffic congestion caused by the directional imbalance of the traffic flow and improve the utilization rate of urban road resources. This paper proposes a dynamic allocation model for reversible lanes for road sections and intersections in the intelligent vehicle infrastructure cooperative system (IVICS). The dynamic lane allocation model for the road sections is constructed based on the Bureau of Public Road (BPR) function, in which the 24 hours of the day are divided into stages, the traffic volume and road impedance of each stage are obtained, and their product is integrated over time. Finally, the plan with the least delay in each stage is selected as the optimal solution. The dynamic lane control model for intersections is built according to the Highway Capacity Manual 2000 (HCM2000) delay model. With the minimum average delay of vehicles at the intersection as the objective function, the average delay of different lane combinations under different traffic conditions is analyzed to find the optimal combination of reversible lanes and ordinary lanes. The model is verified by case analysis and MATLAB calculations. The results show that the reversible lane dynamic control model can effectively allocate road resources and reduce driving delays.

River connectivity restoration for upstream‐migrating European river lamprey: The efficacy of two horizontally‐mounted studded tile designs

AbstractMany rivers are heavily fragmented, resulting from anthropogenic cross‐channel structures. Cost‐effective solutions are needed to restore habitat connectivity for migratory fishes, including those of conservation concern, such as the European river lamprey (Lampetra fluviatilis). Studded material is becoming increasingly used as a low‐cost retrofit solution for lamprey passage at sloping weirs, although little is known about the efficacy of the material or what stud arrangements may be most effective. This study tested whether expanding a single‐density studded tile (SDT) lane from 1 to 2‐m width increased passage success (nreleased = 133), and also compared the passage performance between a SDT lane and a dual‐density studded tile (DDT) lane (nreleased = 115) at a sloping weir, using PIT telemetry. No passage was recorded (nattempted = 89) at the 2‐m wide SDT lane, but 61.6% (npassed/attempted = 53/86) passed using DDT/SDT lane combination. However, increased passage efficiency was likely a result of high river flow (Q2.0‐Q30.6) during DDT/SDT comparison versus low (Q8.3‐Q88.5) while the 2‐m wide SDT lane was employed. There was no evidence that passage occurred using solely one stud configuration. It is, therefore, hypothesised that passage of river lamprey at weirs is more dependent on flow regime than the provision of either stud configuration. However, with 46.1% (npassed/released = 53/115) of those released during DDT/SDT comparison passing on the instrumented section (10.5% of weir face), the provision of studded tiles may aid in lamprey passage at high flows, presumably as the tiles generate a low‐velocity boundary layer that can be utilised as lamprey swim above the studs.

Reversible lane network design for maximizing the coupling measure between demand structure and network structure

This paper investigates demand-originated reversible lane design plans for transportation networks, where the tidal and asymmetrical characteristics of the demand structure are taken into consideration. Compared to traditional network design methods, this reversible lane technique has some advantages. It not only can improve the performance of the considered network by taking full advantage of the potential resources and existing infrastructures but is also easy to operate, returns rapidly, is less costly and requires no additional land. Specifically, this study first defines a coupling measure to quantify the relationship between network structure and demand structure. Then, focusing on maximizing the coupling measure, a nonlinear bilevel mixed-integer programming model is presented to find the optimal lane combination strategy in the considered network from the viewpoint of systematology. For solving the proposed model, we design heuristic algorithms to obtain its approximate optimal solution. Finally, the effectiveness of the proposed approaches is examined on the Sioux Falls network and Beijing main road network.

The advantages of the original combination over narrow lane combinations in multi-frequency GNSS orientating

The advantages of the original combination over narrow lane combinations in multi-frequency GNSS orientating

The optimal narrow lane combinations for multi-frequency GNSS orientating

The optimal narrow lane combinations for multi-frequency GNSS orientating

Adaptive Kalman filter based on variance component estimation for the prediction of ionospheric delay in aiding the cycle slip repair of GNSS triple-frequency signals

In order to incorporate the time smoothness of ionospheric delay to aid the cycle slip detection, an adaptive Kalman filter is developed based on variance component estimation. The correlations between measurements at neighboring epochs are fully considered in developing a filtering algorithm for colored measurement noise. Within this filtering framework, epoch-differenced ionospheric delays are predicted. Using this prediction, the potential cycle slips are repaired for triple-frequency signals of global navigation satellite systems. Cycle slips are repaired in a stepwise manner; i.e., for two extra wide lane combinations firstly and then for the third frequency. In the estimation for the third frequency, a stochastic model is followed in which the correlations between the ionospheric delay prediction errors and the errors in the epoch-differenced phase measurements are considered. The implementing details of the proposed method are tabulated. A real BeiDou Navigation Satellite System data set is used to check the performance of the proposed method. Most cycle slips, no matter trivial or nontrivial, can be estimated in float values with satisfactorily high accuracy and their integer values can hence be correctly obtained by simple rounding. To be more specific, all manually introduced nontrivial cycle slips are correctly repaired.

An Indefinite Cycle Traffic Light Timing Strategy

Intelligent transportation signal control plays an important role in reducing traffic congestion and improving road capacity. The key of signal control is to adjust the traffic lights appropriately according to the traffic flow, which is an adaptive control. In this paper, we propose a new timing strategy. This strategy includes green time optimization and lane combination calculation. According to the real-time traffic flow, we optimize green time and calculate lane combination to adjust the cycle and then we can get the timing plan. The simulation results of random data and actual traffic data show that the strategy we proposed can increase traffic efficiency by more than 15% at intersections, reduce vehicle detention, and relieve traffic congestion.

Exploring Multiplier Effects Generated by Bus Lane Combinations

Numerous studies have explored design and evaluation of bus lane priority by using empirical, analytical, and simulation approaches. However, none attempted to understand how different bus lane combinations, such as continuous and discontinuous bus lane sections, and a different number of bus lane sections, affect bus performance and general traffic. This paper investigates operational effects of bus lane combinations to establish whether multiple bus lane sections create a multiplier effect in which a series of continuous bus lane sections creates more benefits than several single-lane sections. If a multiplier effect exists, it suggests scale economies in wider implementation of bus priority on a networkwide scale. Overall, results confirm that there is a multiplier effect; thus bus travel time benefits and general traffic travel time disbenefits are proportional to the number of links with a bus lane. The effect suggests a constant return to scale on continuous multiple sections. The results also suggest that converting a traffic lane to a bus lane when the upstream traffic volume exceeds the capacity of the remaining traffic lanes causes significant negative effects for buses and general traffic. In addition, negative general traffic effects of continuous bus lane combinations are lower than those for a similar number of discontinuous bus lanes. Bus delays at intersections approaching the bus lane tend to improve when upstream traffic volume does not exceed the capacity of remaining downstream traffic lanes. Policy implications and areas for future research are suggested.

Ambiguity Resolution with Single Epoch for GNSS Reference Network Based on Atmospheric Delay Information

Correct resolution of ambiguities for GNSS reference network is prerequisite for generation of corrections for network RTK. Due to the presence of atmospheric delay in the double-differenced observations, the convergence time of ambiguity is about a dozen minutes and even dozens of minutes for medium and long baselines. And in the case of loss-of-lock or new rising satellites, the integer ambiguities have to be redetermined over and over again. But for the application of GNSS network RTK, the resolution of ambiguity needs to be determined real time as possible. Atmospheric delays of previous epochs are used to predict atmospheric delays of following epochs, and then wide and narrow lane combination of carrier-phase observations as well as ionosphere-free combination is used to resolve ambiguities with single epoch. Our test results show that the precision of predicted double-differenced tropospheric and ionospheric delays is about 2-3 cm using temporal-and spatial-correlation exponent model, and the success rates of L1 ambiguities resolution with single epoch reach above 90% for medium and long distance GNSS reference station network.

Evaluation of Design Standards of Four-Hour Volume Traffic Signal Warrant

Traffic signal warrants set the minimum conditions under which a traffic signal installation may be appropriate. The four-hour volume signal warrant in the current Manual on Uniform Traffic Control Devices (MUTCD) (FHWA 2009) is applied based on a set of critical vehicular volumes for different lane combinations of major and minor streets. This paper describes an effort to apply microscopic simulation to evaluate the critical volumes used in the four-hour warrant. The results show significant differences in average control delay for minor street traffic under different volume combinations, lane configurations, turning volume percentages, heavy vehicle percentages, and the number of major street lanes (four versus six lanes), most of which are not currently considered in the four-hour warrant. This finding provides some evidence of the need to possibly revise the critical design values of the current four-hour volume warrant.

Operation and Safety of Right-Turn Lane Designs

The objectives of this research by the Texas Department of Transportation were to determine the variables that affect the speeds of free-flow turning vehicles in an exclusive right-turn lane and explore the safety experience of different right-turn lane designs. The evaluations found that the variables affecting the turning speed at an exclusive right-turn lane include type of channelization present (either lane line or raised island), lane length, and corner radius. Variables that affect the turning speed at an exclusive right-turn lane with island design include (a) radius, lane length, and island size at the beginning of the turn and (b) corner radius, lane length, and turning-roadway width near the middle of the turn. Researchers for a Georgia study concluded that treatments that had the highest number of crashes were right-turn lanes with raised islands. This type of intersection had the second highest number of crashes of the treatments evaluated in Texas. In both studies, the “shared through with right lane combination” had the lowest number of crashes. These findings need to be verified through use of a larger, more comprehensive study that includes right-turning volume.

Use of individual race results in the estimation of genetic parameters of trotting performance for Finnhorse and Standardbred trotters

The heritability and repeatability for trotting performance traits were estimated from individual race results. Data comprised of records from 1991 to 1995 for 4808 Finnhorses and from 1993 to 1995 for 5869 Standardbred trotters. The statistical model included the additive genetic effect of an animal and two permanent environmental effects, and the fixed effects of sex, age, starting method*starting lane combination, driver and race. The first permanent environmental effect described repeatability over a horse’s career while the second one characterized repeatability within a racing year. Variance components for three trotting performance traits were estimated by the animal model and the method of restricted maximum likelihood (REML). Heritability and repeatability estimates were moderately high for time at finish (h 2 =0.23–0.28 and r=0.50–0.57), moderate for ranking within a race (h 2 =0.12 and r=0.25) and low for earnings (h 2 =0.05–0.09 and r=0.15–0.18). Time at finish seemed to be the most usable measure of trotting performance because of its wide information substance. However, time at finish does not take into account records of disqualified horses or of those which did not finish, but use of earnings, either from individual race results or preferably from annual records, is one possible way to consider records of such horses.;

Development of Expected Conflict Value Tables for Unsignalized Three-Legged Intersections

A high percentage of highway crashes in the United States occur at intersections. These crashes result in property damage, lost productivity, injury, and even death. Identifying intersections associated with high crash rates is very important to minimize future crashes. Identifying the high-risk intersections before crashes occur is a challenge that every traffic/safety analyst faces. Traffic conflict technique is a solution to this problem. Extensive research efforts have been made to estimate mean and abnormal traffic conflict counts at four-legged intersections with varying lane and approach volume conditions. However, similar efforts on unsignalized three-legged intersections have been focused only on two-lane highways. Therefore, a thorough analysis of conflicts at unsignalized three-legged intersections with various lane combinations was necessary. The current study is part of a comprehensive research attempt to develop expected conflict value tables that can be easily used for different intersection configurations. The most common unsignalized threelegged intersection types (total of three) were identified and categorized based on through lanes of the intersection. During the summer of 1995, 12 different traffic conflict types were surveyed from 38 intersections randomly sampled from a five-county area in west-central Florida. Combining a recent 3-year crash history and the collected conflict data of the sampled intersections, new and easy-to-use tables were developed for Florida-based unsignalized three-legged intersections. The tables provide mean, variance, and 90th and 95th percentile conflict rates. These simplified tables can be used to estimate the expected number of crashes, relative safety effectiveness, and operational problems at intersections.