Highway Research Record

EXECUTIVE SUMMARY

In the General Report on Road Research Work done in India for the year 2004-2005, published as the Highway Research Record No. 32, the research work done by 25 organisations on various aspects has been reported. The report has been compiled by CRRI. The R&D work is reported under the following five major Areas and the Research work done in Academic Institutions related to the thesis work
1. Highway Planning, Management, Performance Evaluation and Instrumentation
2. Pavement Engineering and Paving Materials
3. Geotechnical Engineering
4. Bridge Engineering
5. Traffic & Transportation Engineering

I. Highway Planning, Management, Performance Evaluation & Instrumentation

1.1 Highway Planning & Management
Preparation of master plan for rural roads in 22 districts of Jharkand has been reported. Core network and DRRP Maps have been prepared for these districts on 1:50,000 scale in GIS environment. Efforts have been made to provide 100% connectivity to habitations at block level. The final maps and related data base for habitation and road inventory have been submitted to REO, Jharkhand. Preparation of master plan for rural roads in districts of Bihar, DRRP and CNP Maps have been digitized for all districts of Bihar State. The objective of the project for the development of data center for NHs using GIS is to establish a data center in GIS environment on pilot scale basis. The database can be easily updated, retrieved and monitored from time to time. Initially, Haryana State has been identified on pilot scale basis. Results of the study are expected to lead to better planning and maintenance of NHs. Enlarging the scope of study a new project on National data center has been reported. The objective of the project is to establish a GIS based database for NHs in the country. The scope of the proposed database includes road inventory, road condition, land use and road side utility services, which will allow research leading to development of GIS based road information management system. Further, PMS will be developed for the NHs and it will be integrated with GIS for monitoring, retrieval and updation. TRL, U.K. entrusted CRRI to prepare country paper covering various aspects under road project appraisal process in India which are practised in the country like road planning, institutional and administrative framework, road project appraisal process etc. Under road maintenance plan for ring road of Delhi using HDM-4 and GIS the data related to Ring Road, maintenance strategies have to be evolved for the entire section. The work programme has been developed for the duration of 10 years using HDM-4. Under development of GIS for Pradhan Mantri Gram Sadak Yojana (PMGSY) roads, a Graphical User Interface (GUI) has been created for rural roads network in Tamilnadu State, which can be in the data format compatible to the requirements of the users. Using GUI, it will be easy to determine proximity between features, length of road, retrieval of data using query option etc.


1.2 Pavement Evaluation
The R & D work reported under the sub-area includes an ongoing project on riding quality of highway pavements in Tamil Nadu. Periodic data on pavement roughness obtained through Bump Integrator was analysed for arriving at correlations between various pavement surfaces. New projects taken up under pavement evaluation include pavement condition assessment and roughness measurements of Delhi-Agra (NH-2) and Delhi-Jaipur (NH-8) highways, equivalent half space model for evaluation and design of airfield pavement, road condition surveys of selected network of State Highways (SH) and Major District Roads (MDR) of Mizoram State. The information / data collected on pavement condition assessment and roughness measurements of Delhi-Agra (NH-2) and Delhi-Jaipur (NH-8) highways would be applied for assessment of maintenance inputs provided on the highways and the quality of maintenance works done. Pavement condition and roughness on majority of road length was found to be satisfactory. The results obtained using equivalent half space model and those obtained by using multi-layered elastic theory are comparable with respect to pavement classification number (PCN) results and design overlay for airfield pavements. Majority of the roads surveyed for the selected network of State Highways and Major District Roads of Mizoram State were found to be in poor condition. These sections were found to be in dire need of strengthening, requiring major rehabilitation and improvement works.

1.3 Instrumentation
As on ongoing project reported in the instrumentation area, a Road Condition Evaluation System has been designed and fabricated for Andhra Pradesh PWD. The system is capable of measurement of Road Geometrics (road roughness, vertical gradient and horizontal curvature) and Road Condition Evaluation (crack, pothole, patch work, ravel etc.). The system provides measurements quite fast vis-à-vis manual measurements and without dislocating the traffic. Field results obtained using this system are very good. Another project reported on Development of Micro-Processor System for Roller Mounted Nuclear Density Gauge is in progress. Under this project laboratory studies have been carried out with the system on different density standards and a calibration equation between the density and the gamma counts has been established.

2. Pavement Engineering and Paving Materials

2.1 Soil Stabilisation, Low Grade Materials and Low Volume Roads
New projects on determination of percentage of lime required for lime stabilization of various types of clay soils, study on suitable measures for road construction in presence of harmful salts in UP, use of fly ash for rural road construction near Dandeli, Karnataka and study of reconstruction of rural roads in lieu renewal work, where the proper design measures were not under taken have been reported by different organizations. The study on harmful salts is to develop the new method of construction of road in areas where these are present in the soil and to study the practices adopted for construction of road in such areas. A project on information database on use of waste and recycled materials in highway applications has been reported. The database contains a pictorial representation of the geological distribution of production and use of such materials along with their engineering properties i.e., a description and tabular listings of the physical, chemical and mechanical properties as well as environmental properties. A project on the use of ash generated from Surat Lingnite power plant for stabilization of different types of clayey soil is under progress.

2.2 Flexible Pavements
A study on field trials of application of Cationic Bitumen Emulsion for Binder Economy has been reported. The field trials were reported to be carried out on 2 km test track on NH-2 near Agra. The performance of Mixed Seal Surfacing (MSS), Pre Mix Carpet (PMC) and Two Coat Surface Dressing (TCSD) has been reported to be satisfactory. In a study on commercial production of Multigrade Bitumen, it has been reported that Multigrade Bitumen has high penetration index and improved resistance to temperature susceptibility. A study on field trials of Cationic Bitumen Emulsion for optimization of binder quantity in bituminous surfacing revealed that construction of roads with emulsion based cold mix technology adopting specifications of close-graded premix carpet, mix seal surfacing, premix carpet and two coat surface dressing is possible on high volume roads such as National Highways. A study on use of Natural Rubber Modified Binder (NRMB) and Crumb Rubber Modified Bitumen (CRMB) in bituminous surfacing under different climatic conditions showed that NRMB and CRMB mixes had improved Marshall quotient of SDBC. The failure temperature of modified mixes is 8-10 ºC higher than conventional bitumen. Performance of NRMB section is better than 60/70 bitumen in high rainfall area. A study of Microsurfacing studies in Guwahati has been reported. The study found that Microsurfacing is quick and environment friendly technology which can be used for preventive and periodic maintenance of pavements. A study on impact of Flakiness and Elongation indices on performance of Drained Modified Bitumen (DMB) has shown that the flakiness index plays a vital role in the performance of DMB mixes. Increase in combined flakiness and elongation indices from 30 to 60% resulted in a poor mix in terms of its volumetric properties and also laboratory performance studies. Study on Drain Asphalt Additives in Porous Asphalt has shown that Japanese specifications for grading of porous asphalt mixes with 60/70 paving grade bitumen and 1% Drained Asphalt Modified Additive (DAMA) as an additive can be used in India for better performance of porous asphalt mixes. A study on development of material for special road application (Noise Absorbing Porous Bituminous Concrete) has revealed that porous bituminous concrete mixes can be used for roads near hospitals, schools and residential areas for abutment of noise pollution. Study on Recycling of Pavement Materials showed that by adopting the recycling process, significant savings could be achieved. The savings can be increased further if demand of fresh aggregates for gradation correction is minimized. Besides, the savings in direct cost, significant indirect cost savings in terms of conservation of materials and energy as compared to the construction of new pavement structure can be achieved.

2.3 Rigid Pavements
A completed project reported on partial substitution of wollastonite in concrete mixes revealed that compressive strength of concrete is improved by 20 and 30 percent at 28 & 56 days respectively and the improvement in flexural strengths is of the order of 30 and 40 percent at the same ages, thereby, resulting in an overall economy of 10 to 15 percent in the cost of construction of concrete pavement. The other completed project reported on investigation and suggestion for rectification of cracked slabs of NH-4 (km 515- km 592) revealed that the causes of cracking of newly constructed two lane rigid pavement may be due to various reasons such as delayed joint cutting, construction on gradients, settlement of subgrade and plastic shrinkage cracks. The remedial measures suggested for improving the pavement included sealing of cracks with epoxy resins, crack stitching and sealing, full depth repair of damaged portion of slab and slab replacement in heavily cracked panels. An on-going project reported as study on strength and durability of plain and reinforced concrete using blended cements made by replacing OPC with 15,25 &35 percent of flyash and 35, 50 and 65 percent of ground granulated blast furnace slag revealed that with 15 percent flyash the compressive and flexural strengths are at par with OPC concrete upto the age of 28 days. However, at longer ages, the strength characteristics are improved in all cases. Corrosion study reported up to the age of 270 days showed no signs of corrosion in blended cement concrete with cover thickness of 45 and 70 mm.

Research projects on use of Marble Slurry Dust (MSD) in high performance concrete and use of sulfonated melamine formaldehyde superplastizer (SMF) and flyash in cement concrete have been reported for the first time. Use of marble slurry dust in high performance concrete has been reported to develop high performance concrete by partial substitution of sand. Also the use of flyash, silica fume and mineral / synthetic fibres along with admixtures have been reported to improve workability of concrete. Use of SMF superplastizer and flyash in cement concrete roads has been reported to study the rate of increase in compressive strength and performance of C.C. roads. The aspects related to environment, benefits and economy in the cost of construction of concrete roads are being studied.

3. Geotechnical Engineering
Landslide hazard mitigation, use of waste materials and ground improvement techniques are the major R & D areas pursued by different organizations during the year. The investigations and remedial measures on rockfall problems on Phuentsholling-Thimpu Road, Bhutan, study for landslide and rockfall problems on Mumbai - Pune Expressway, instrumented monitoring of Patalganga landslide on NH-58 in Uttaranchal, and investigations for sinking of highway stretch on NH-54 in Mizoram, simulation modelling of rainfall induced landslides and finite element seepage analysis for slope stability are the projects undertaken to study the landslide problems. A project on prevention of cut slopes along approach road from Naihar village to bridge point at Koldam in Himachal Pradesh and preparation of GIS based subsurface geotechnical map of Delhi have been reported. Design of road embankment using fly ash, ground improvement measures for widening of industrial bypass road at Vishakhapatanam and monitoring of highway embankment in Vishakhapatnam Port area for efficiency of Band Drains used to stabilize the highway stretch have been reported in the area of ground improvement techniques.

4. Bridge Engineering
Research projects on dynamic response of prestressed concrete bridges and creation of national test facility, formulation of guidelines, specifications, manual of practice for design and execution of expansion joints have been reported for the first time. In dynamic response of prestressed concrete bridges (PSC), study on development of realistic modelling of prestressed concrete bridges, taking into account the time dependent non-linear effect of creep & shrinkage has been reported. Based on this modelling, computer software will be developed. Further study on dynamic tests in linear / non-linear field is proposed to be carried out to find out the dynamic response of PSC bridges. The project on creation of National Test facility, formulation of guidelines, specifications, manual of practice for design and execution of expansion joints aims to develop the testing facilities to evaluate bridge deck joints at CRRI. The National Test Facility will help to devise rationalized acceptance criteria for bridge expansion joints before their installation in the field. This will ensure better field performance throughout the service life of expansion joints and encourage the manufacturers to produce innovative expansion joints indigenously.

Some of the projects reported in the area of Bridge Engineering include Study on Hard Topping for Distressed CC wearing coats and Concrete Pavements, Creating a data base on bridge information System for the State of Tamil Nadu, Creating a database to analyse the pile load test, Distress Diagnostic, Performance Evaluation and Bridge Management System for Concrete Bridges. In the project, study on hard topping for distressed C.C. wearing coats and concrete pavements, the aim is to develop proper cement and polymer based concrete for repair works and to study the effectiveness. The project on creating a data base on bridge information system for the state of Tamil Nadu aims to develop an inventory of bridges on various categories of roads in Tamil Nadu MS ACCESS programme classifying the data into 17 different aspects for each bridge. The bridges will be given numbers and the same will be intimated to the Divisional Engineers of Highways. The creation of database to analyse the pile load test conducted by Highways Research Station is to arrive at ultimate load adopting different approaches and comparing the same with the theoretical ones. In the project on distress diagnostic, performance evaluation and bridge management system for concrete bridges, the objective is to develop a suitable technology in terms of methodologies/algorithms (for development of software) and necessary hardware (instruments/techniques) applicable to different concrete highway bridges in the country for Bridge Management System. The study is confined to bridges of type T-beam girder most commonly employed on highways in India. Validation of the same will be done on other bridges, if possible. One project reported as completed is on the studies for Aerodynamic Stability of Cable Stayed Bridge Decks, under MORTH Research Scheme. The work is limited to aerodynamic stability of cable stayed bridge decks. Efforts are being made to investigate the aerodynamics of other type of bridge decks used in long span cable stayed bridges. Further wind tunnel studies are to be carried out to understand the aerodynamic effects on pylons of different configuration and cables of different diameters.

5. Traffic and Transportation

5.1 Planning and Management
Under the project on Transport System Management Plan developed for the Chandani Chowk area in Delhi some action plans had been reported that need to be implemented for the efficient and safe operation of traffic in the area. This includes running of battery-operated buses, banning cycle-rickshaw traffic during peak hours, creation of multistory parking facilities at Meena Bazaar and parade ground of Red Fort to accommodate atleast 5,000 cars and 5000 two-wheelers. The feasibility study of construction of a pedestrian subway near bus stand at Govindgarh, Punjab reveals the peak hour vehicular traffic at about 3,500 vehicles and the peak hour pedestrian flow crossing the NH -1 at about 830. It was observed that the hazard index was more than the critical value which warranted the provision of pedestrian subway at NH-1. The feasibility study for providing the subway for right turning traffic on Netaji Subhash Marg near parade ground, Delhi indicated that there will be a total saving of Rs.32 000/- per day which amounts to Rs.96.00 lacs per annum due to expected increased speed resulting from the construction of underpass. EIRR from 15 years return period was found to be 46.2 per cent which indicates that construction of underpass was economically viable even when idling time is not taken into consideration. The study on trucks transportation on NH-4 connecting Chennai indicated that the movement of truck on NH-4 is in large numbers and the majority of the trucks were carrying industrial goods to and fro Chennai. The movement of petroleum products was minimum to Chennai and petroleum product transported out of Chennai was maximum. A study was carried out on the interchange at Noida Toll Road and Ring Road in Delhi to evaluate two design options proposed by the PWD and NTBCL. After making critical evaluation, it was observed that the design proposed by PWD Delhi was better than the design proposed by the NTBCL, as in this design no immediate expenditure for any structure was needed. A study on heterogeneous traffic flow modelling for India reveals that this model can be developed at network level with proper validation at link level. The estimation of fuel loss at New Delhi Railway Station indicates that due to low running speed and delay, the estimated fuel loss was more than Rs. 3.00 crores per annum, and the annual time loss was Rs.2.4 crores. Keeping in view the problems, the short and long term measures were suggested to minimize the delay and subsequently the fuel loss. The comprehensive traffic and transportation study of Surat city had recommended various intersection improvement plans and traffic management plans. Majority of these measures were implemented by local authorities. The study of impact of new high rise buildings on road traffic at Tardeo, Mumbai had recommended that the construction of new link from the proposed residential complex will facilitate traffic emerging from the proposed residential complex to use relatively less congested roads which would act as an alternative road link for the distribution of traffic towards the island and suburbs of the city. Some new projects on evaluation of urban speed limits on arterial roads, congestion mitigation in urban areas and modelling generalized cost of travel have also been reported.

5.2 Safety and Environment
Study of accidents on Inner Ring Road, Chennai reveals that total accidents are high during the night hours. Also the pedestrians, cyclists and two wheeler riders are involved in large numbers in these accidents. A study carried out on the subject of pedestrian safety at Chennai Mofussil Bus terminus recommends that immediate attention should be paid towards the safety of pedestrians on Inner Ring Road. Other recommendations for the study include providing a pedestrian overbridge on Inner Ring Road at Chennai Mofussil Bus terminus, proper location of bus stops, adequate lighting facilities and proper signages etc. Six Chemical formulations, three for white paint and three for yellow paints were evaluated for durability and photometric performance. The study showed that two formulations have useful life of more than 14 months. The main recommendations of the study on Urban Transport Environment Interactions indicate for staggering of office hours, traffic control measures, exploring the possibility of alternative fuels, reduction of the present level of sulphur content in diesel etc. Post study on improvements to accidents – prone spot in Tamil Nadu suggests measures and indicates that works carried out resulted in elimination of accidents. Study on Road Traffic Safety in Ahmedabad city recommends future action plans in order to minimize accidents. A Nationally Coordinated Project on Road Traffic Safety carried at on NH-58 concludes that at most of the problematic locations, the spot speed is high. Pedestrian flow is very high on both along and across the road. There are encroachments of shoulders by the shop-owners alongwith high volume of vehicular traffic. The salient findings emerging from the study of measurement of vehicular pollution at selected intersections are indicative of the fact that vehicular emissions were predominant contributors to the observed air quality on the kerbside . However, particulate matter (PM10) and other pollutants were not observed to be consistent with traffic, which might have been contributed from other sources. A new project on road accident modelling for highway development and management in developing countries has been taken up for which road accident frequency on two-lane undivided rural highways was modelled as a long-linear function of classified traffic volume, member of public/private accesses, condition of carriageway/shoulder and off-shoulder hazard rating.

6. Research Work Done in Academic Institutes Related to Thesis Work

The salient features of some of the completed projects are:

1. A study on Project Management revealed that in linear projects with full span of uniform progress rates, all activities become critical when the least time and least distance intervals between any two consecutive activities are the same at the start and at the end of activities or when the succeeding activity starts only on the completion of the preceding activity.

2. A Study on Effect of Pavement Unevenness on Capacity of Two Lane Roads has shown that the Free Flow Speed of a vehicle decreases with the roughness of the road surface. The effect of roughness is more apparent on the speed of passenger cars than of heavy vehicles. The PCU for a vehicle type decreases linearly with roughness. Non-motorized vehicles are not influenced much by road roughness while the speed of motorized vehicles is greatly influenced. The speed–volume relationships drawn at different sections of two-lane road indicate that the capacity decreases with an increase in the road roughness.

3. The factors that mainly affect the performance of rural roads are identified as construction quality and drainage. Neural network models were developed for construction quality and drainage. The main distresses identified on these roads were raveling, pothole, and edge failure. These distresses were modeled in neural network for the selected rural roads.

4. A multinomial logit model is used to analyze overtaking decisions. The best fitting model is obtained by testing various utility specifications. The final model provides a good fit (83%) with the observed empirical data. it was observed that the key factors that influence partial overtaking behavior include: type of overtaking vehicle, lateral spacing at diverging opportunity, and speed difference. The results also indicate that two-wheelers are more likely to overtake than other vehicle types. Further, with increasing speed difference full-overtaking manoeuvres are more likely. The lateral spacing at the diverging opportunity is correlated with increasing full overtaking propensity, whereas, the lateral spacing at the merging opportunity appears to be negatively correlated.

5. The recycling process is a viable technology. The aged bitumen can be rejuvenated back to its original form in terms of penetration value, softening point and ductility. The aged bitumen having penetration value of around 40, softening point of 53 degree centigrade was rejuvenated to penetration and softening point values of 65 and 54 degree centigrade respectively after the addition of optimum rejuvenator content. By adopting the recycling process, cost saving to the tune of 23% per lane per km can be achieved. This can go up if the fresh requirement of aggregates required for the gradation correction is less. Besides the saving in direct cost, there are significant indirect cost savings in terms of conservation of materials and energy.

6. A suitable formulation using optimization as a tool has been developed which provides a rational basis of choosing the Reclaimed Asphalt Pavement (RAP) quantity. The objective function is chosen as maximization of RAP or minimization of cost. Fatigue and static creep tests are performed on the recycled mixes and compared with the fresh mix. Performances of recycled mixes are comparable to that of mixes prepared using fresh aggregates.

7. Marshall Stability method of mix design was carried out on unreinforced and glass fibre reinforced bituminous mixes to arrive at optimum bitumen and fibre content. From the Marshall Stability tests conducted, an optimum fibre content of 0.3% by the weight of total mix was found for a bitumen content of 4.5%. About 20 to 32 percent increase in stability values can be achieved by reinforcing the bituminous mix with glass fibre. Higher stability values indicate that the reinforced mixes would be less susceptible to cracking of flexible pavements.

8. The depth of rutting is a result of binder properties and mix. It is reported that Olexobit SMA is better in resisting permanent deformation than other binders used.

9. The MORTH specification for combined shape index appears to be extremely severe compared to the Superpave requirement. It is found that a combined index value of about 70% is at par with the 10% requirement of Superpave for 1:5 gauge. The 70% critical shape index value has also been obtained from rutting (static indentation) test results.

10. The resilient modulus value of granular material was found to be significantly affected by the state of stress, presence of moisture and presence of fines. The effective modulus of the granular layer has been found to be a function of different pavement parameters like subgrade strength, bituminous layer strength and layer thicknesses.

11. The workability of bituminous mixes was found to be affected by maximum nominal aggregate size in the mix, aggregate gradation, binder type and content. Compaction temperatures have been suggested for different types of mixes on the basis of workability test results instead of fixing the compaction temperatures on the basis of binder viscosity. Mixes with modified (rubber and polymer) binders were found to be less workable compared to normal mixes.

12. The amount of binder present in a mixture will directly influence the amount of fatigue cracking. When the effective bitumen content is increased in a mix, the amount of longitudinal cracking will be decreased. The air voids within an AC mixture are an important parameter to influence fatigue cracking. Increasing the amount of air voids in the AC mix may significantly increase the amount of longitudinal fatigue cracking.

13. The surface finish produced by self-compacting concrete is exceptionally good and patching will not be necessary. The self-compacting concrete mix had a higher cementious content and contained fly ash when compared to standard concrete mix.

14. The use of coir geotextile as reinforcement in road construction increases the CBR values to the extent of 2%. The non woven coir geotextile is showing better results as compared to woven geotextile.

15. It is reported that the seashore soil of Tanjavur and Pudhukkotai is weak and can be stabilized with cement. An increase in cement percentage increases the optimum moisture content.

16. A study on development of mode choice for a new mode (Delhi Metro) indicated that 65% of the total trips in the corridor are work trips. Waiting time for metro is that of half of the bus and the important variables for the mode choice were found to be in vehicle time and in vehicle cost.

17. A study on integration of GIS and GPS for Travel time behaviour studies reported that geo-referenced map for whole Tiruchirapalli road network was created indicating NH, SH and District roads.

18. A fuzzy inference model, denoting the microscopic behaviour of drivers under varying driving scenarios was developed. Also a relationship between vehicular characteristics and roadway characteristics was established.

19. The economic evaluation of the project involving construction of flyover at signalized intersection done based on estimation of money value of travel time saving using wage-rate approach, has resulted in an IRR more than the market value.

20. Stated preference techniques are found to be instrumental for developing utility models and estimating perceived values associated with various attributes of travel for urban bus users in Kolkata. Using stated preference techniques and MNL, subjective values associated with quantitative attributes like discomfort level, appearance of vehicle and noise level were estimated.

21. Speeds have a very significant relationship with the exhaust emission of a vehicle. Model for estimating ambient concentration of pollutant can be used for long-term prediction for transport environmental planning and management decisions.

22. Interrupted flow conditions for two-wheelers, three-wheelers and cars generally produce higher levels of tail-pipe emissions of CO, HC and NO.