Road Information

10 Commandments of a Good Road

Get Water Away from a Road

  • Drainage cannot be emphasized enough in road construction and maintenance. Water affects the entire serviceability of a road. Too much water in the base materials weakens the road. Water allowed to remain on top of a gravel or paved road weakens the surface and, when combined with traffic, causes potholes, cracking, and rutting. If improperly channeled, water causes soil erosion and breakdown of pavement edges. Whether it's mud in the spring or frost heaves in winter, the presence of water in roads is nothing but trouble.
  • Building and maintaining a good surface drainage system and maintaining it is the best way to lessen water's damaging influence on a road. A proper surface drainage system prevents water from infiltrating the pavement's surface and removes water from the driving lanes in a constant thin sheet to the side ditches which carry the water away from the roadway. Sealing cracks in the pavement surface also helps but this is of little use if the surface drainage system does not function properly. A surface drainage system has four components: road crown, shoulders, ditches and culverts. The crown or superelevation of the road surface allows water to run off to the side ditches.
  • Shoulders are an extension of the road surface and allow for the continued flow of water to the ditches. Ditches are used to carry water away from the roadway. They need to be kept clean and protected from erosion. Water left in the ditch can sometimes leak back into the pavement's foundation materials. Water collected and carried in the ditch has to be directed away from the roadway at frequent intervals, sometimes using culvert pipe. Culverts usually channel water from one side of the road to the other, helping to control the flow of water and slowing it down to reduce erosion.
  • Road managers are guided by the principles that 1 water runs down hill, 2 water needs outlets at the bottom of all grades, and 3 puddles mean problems. If it were not for water, a road commissioner's job would be easy. But because of water, whether in liquid form or as snow or ice, a road manager's work is never done. Except for some moisture that is needed for soil compaction and for dust control, water is the road manager's enemy.

Build on a Firm Foundation

  • A highway wears out from the top but it falls apart from the bottom. This is another way of saying that the road base determines the service life of a road. The base supports everything above it, including traffic. If adequate support does not exist, the road will rapidly deteriorate. A good road requires a suitable foundation which, in turn, requires stable material. A road material is stable if it has little or no change in its volume and does not deform under repeated loads whether the material is wet or dry. 
  • Soils can be stabilized using such agents as asphalt, calcium chloride, cements, lime, salt and other products. To select the proper stabilizing agent, an understanding is required of both the soil and the agent to be used. The additive must be of the correct type and in the correct quantity to produce satisfactory results. Geotextiles may also be very helpful to stabilize a soft road.

Use the Best Soils Available

Roadway Gravel in Maine (PDF)

  • In Maine, natural good-quality gravel is getting to be in short supply. Blended or crushed gravels are more expensive alternatives. The quality of soils used by a town will often depend on local availability and budget. In deciding what is affordable, a town should consider the long-term consequences of using lower quality material. By putting down a good base in the beginning using quality materials, a town can correct the few weak spots in the roads over a period of years and be assured of a sound base upon which eventually to apply a permanent hard surface. 
  • Using inferior base materials may require excessive maintenance during the road's life and perhaps costly rehabilitation before paving. The adage "pay me now or pay me later" applies to road building.
  • Written guides exist to help road commissioners classify the usefulness of soil types for road foundations and bases. The guides give information on potential frost action, compressibility, and drainage characteristics.

Compact Soils Well

  • The denser the materials, the stronger the base. When soil is improperly compacted, future traffic loads or changes in moisture content can cause settlement and failure of the roadway. Compaction is achieved by pressing soil particles together using rollers, tampers, or vibrators, expelling the air from the mass, filling the spaces between the particles, and making the material more dense.
  • Well-graded soils having a fairly even distribution of particle sizes will compact more easily than poorly-graded soils having mostly one particle size. Jagged or semi-jagged particles will compact to a more stable configuration than rounded particles of similar size. A certain amount of moisture is necessary for good solid compaction.

Design for Winter Maintenance

If a town designs its roads for winter maintenance, they would be adequate for the remainder of the year. Consider the following:

  • A one-way plow cuts a nine-foot-wide swath. If the road is wide enough to allow the plow and a school bus to meet, it is wide enough during the remaining seasons of the year.
  • If ditches and roadside areas are wide enough to store snow, chances are they will accommodate spring thaws and heavy water flows.
  • A town will not be sorry for having a wide road but it may regret building a narrow one.
  • Grades should be a minimum of one percent for drainage purposes but should not be greater than ten percent, if at all possible. If the road is steeper than that, it is difficult for heavy equipment to maneuver, especially in wintertime.
  • Sight distance should be considered in designing a road. For safety's sake, a driver should be able to see 75 to 100 feet up the road for every 10 miles of speed. This rule of thumb may be helpful when issuing permits for driveways onto a town road.

Build for Traffic Volumes and Traffic Loads

  • Ice on a pond will support a young skater but it will crack under the weight of an automobile or even break apart. Similarly, a road built to serve residential traffic will break down when it starts carrying a number of large trucks. It takes the passage of approximately 9,600 cars to equal the effect on a road of the passage of one 80,000-pound truck. Road commissioners know that roads, like bridges, should be designed with the expected traffic type and volume in mind.
  • A rule of thumb is to design a road to accommodate the largest vehicle that will use the road under normal operations. Designing the road for the largest piece of town equipment which maintains it in all kinds of weather may suffice. To determine the required depth of base, a common guide is to put in �-inch to one inch of gravel for every foot of traveled way width. For example, a 20-foot-wide roadway should have a minimum of a 15- to 20 inch gravel base. 
  • When considering the type and thickness of pavement mixes to apply on a gravel road, a town is wise to seek some advice. Generally speaking, a low-volume road (300 vehicles per day or less) having some truck traffic may provide good service with a "chip seal." The main function of such a seal is to eliminate the need to replace and reshape gravel, eliminate dust and to prevent raveling of soils. As traffic volumes and weights increase, the type and thickness of pavement should increase to a point where the pavement itself actually shares the load stress. Heavy-duty Interstate highways, for example, have a foot or more of asphalt concrete below the riding surface.

Pave Only Those Roads that are Ready

  • In their haste to put a smooth surface on a gravel road, some towns make the mistake of paving over a road that is not properly prepared. The result may be a complete waste of money. Unless the base of the road is first built with the proper thickness for the traffic it must bear and the gravel is compacted to a proper density with the ability to drain well, any pavement put on it will fail. Experienced road commissioners make sure a gravel road works well before paving. The cost of reconstructing a failed road is must higher than doing it right the first time.

Build from the Bottom Up

  • A road that has a poor base and poor drainage cannot be adequately improved with a top dressing of gravel or new pavement. It may be necessary in some cases to dig out the old road, put in new material and build up the road in layers. Before doing anything to correct a road surface problem, road managers should take into consideration what is causing the problem underneath. Improper drainage, insufficient depth of base or poor quality gravel may be the culprits. These should be corrected before spending money on the surface.

Protect Your Investment

If worn roof shingles are not replaced and if the outside is not painted occasionally, a house will deteriorate and lose value. Roads and bridges also need regular maintenance to keep them from deteriorating. The increased weight and frequency of traffic on Maine roads combined with our adverse weather conditions, mean an increased rate of road and street deterioration. Regular road and bridge maintenance preserves our road investment and prevents costly major rehabilitation later on. 

Maintenance activities include:

  • Roadway Surfaces - blading and shaping, patching, resurfacing; dust control; snow and ice removal
  • Drainage - cleaning and repairing culverts and ditches
  • Roadside - cutting brush, trees and grass; repair and prevention of roadside erosion
  • Bridges - channel clearing; repair of rails, decks and structure; cleaning and painting
  • Traffic Services - sign maintenance
  • Special Projects - restoration or improvements; emergency work such as removing slides and repairing retaining walls.

Keep Good Records

  • Road commissioners know their roads like the back of their hand. Most of them are a walking history book when it comes to the roads they manage every day. This knowledge is of little use, however, when the road commissioner is laid up or retires.
  • Good record keeping makes roadwork much easier for everybody. It's easier to draw up budgets and to show citizens plans for roadwork. Recording what type of work was done on a road or bridge, when, and what materials were used can help a lot in decision-making later on.
  • Towns can start by inventorying all roads and bridges, listing length, width, surface types, culverts, problem areas and other items. Putting these items on a map helps. Next comes listing and prioritizing needed improvements, putting a price tag on them and knocking off a few problems each year. Good record keeping of road and bridgework and equipment is good business. Several user-friendly software programs exist to help towns in this effort, and are available at the Maine Local Roads Center at 1-800-498-9133.
Road Management

Developing a Legal Road Inventory

Road System Management Software (RSMS11 and RSMS16)
Managing a local road budget and determining which road gets fixed can be a very daunting task-and be controversial. The Center has developed some inexpensive and easy-to-use software which can provide the basis or background to making these decisions on how/what/how much/where repairs will be done across a community. Many municipalities across Maine and other states have used this software to develop and support a road budget. In many cases, the software has been used to justify some relatively large road bonds.

While this software is not a highly technical analysis of a road network, it is very powerful, low cost, and easy-to-use by any level of computer user. If your community wants to take a highly technical approach to road planning with deterioration rates and pavement condition index numbers, there are several other more expensive products on the market.

There are 2 software products available from the Center, RSMS16 and RSMS11.

  • RSMS16 Informational Brochure
  • RSMS16 is the latest product and expands the end products of RSMS11. It provides a map of your community with color coded road segments showing the different levels of suggested road repair strategies. It also includes a sign management feature where a Maine community can inventory and assess the number and conditions of all its roadway signs. At this time, this version is not applicable to non-Maine communities. However, if you are not in Maine, please call us because there are options available to customize the software for your use.
  • SMS16 (located at ) is a major upgrade to RSMS 11 software and it will allow anyone to download and use the software using a sample town map before requesting a license to download their own town map. It still functions like RSMS11 but it now produces a color coded map of a Maine town or city showing all road and sign data with their geographical locations.
  • Sign data can be collected and entered directly into the program using a GPS antenna, or information can be gathered in the field for subsequent entry into the program. Among other features, RSMS 16 enables the visual display of road maintenance conditions in a map format, where each road section is color-coded based on its current maintenance category (no maintenance, routine, preventive,rehabilitation and reconstruction). The software also allows viewing aerial imagery, google maps and MaineDOT’s mapviewer.
  • The cost is $195 to new Maine municipality users, $100 to current RSMS11 users, and $500 to private agencies. The cost includes the software, user guide and distress manual, and free technical assistance.
  • RSMS11 Informational Brochure
  • RSMS11 is the original software and is available to any community. Using your road inventory, you can do a “condition survey” of both paved and gravel roads. It will take that information and combine it with some default repair strategies, or your own costs, to produce a list of suggested repairs for each road segment with estimated costs. It also summarizes all your road conditions into a five-level bar chart.
  • The program is available at and it will allow anyone to download and use the software for up to 10 roads. You will need to request a license from the actual computer that you will be using the software on and then we will send you a code via email to lift the 10 road section limitation once we receive your payment.
  • To understand and use this program, it is highly recommended to take the training program; however, it is not critical. The RSMS11 course explains the road surface management process in straightforward, easy-to-understand terms to town officials and road people in local communities throughout Maine and the rest of the country. The training manual covers many subjects, including the software user's guide, identifying distresses, and the overall concept of road management. Upon download, the program comes with the software user’s guide, manual on identifying pavement and gravel distress and free tech support from the Maine Local Roads Center.
  • The actual data collected with this software includes:
    • A town's entire local road network,
    • Condition surveys and their results
    • How to interpret the surface distress information gathered, and
    • How to arrange the findings into a form that is useful to local decision makers who must produce fundable road maintenance programs.
  • Results from the data collected include:
    • Entire road network conditions
    • Budgets for capital/maintenance options
    • Budgets per year/per road
    • Many options to arrange the findings into a report that’s automatically generated that is useful to local decision makers who must produce fundable road maintenance programs.
  • The methodology and software for this system are flexible enough to accommodate the needs of all users in a simple, direct, and easily applied manner. The goal is to identify which road maintenance techniques should be considered for individual roads or streets in a particular local street network.
  • The system is generic and is simply a tool to manage a local road network. Its optimum value is when a town "customizes" the system with its own repair techniques and local costs.
  • RSMS 11 should give town officials the knowledge to plan and carry out road management practices applicable to their own specific needs. RSMS was originally introduced to Maine municipalities in 1990 and many, many towns/cities have used RSMS to "defend" their road maintenance budgets. It is common to find road budgets which leveled off or increased in many Maine towns because of the presence of a "system" for road work. Having a written plan makes a HUGE difference when planning and funding road work.
  • The RSMS software will run on the following operating systems: "Windows XP, Vista, and Windows 7, 8, 8.1 10; 32 or 64 bit". Also included is a Workshop Notebook. The cost structure is as follows:
    • Maine municipalities: $75.00
    • All other public agencies: $150
    • Private agencies: $300
Trees and Roads

As the Pine Tree state, Maine is largely covered by trees and most of our 22,800+ miles of public roads have trees along them. Knowing that many motor vehicle fatalities and injuries occur when a vehicle leaves the road and hits a tree, the MaineDOT and municipalities have the authority to control their rights-of-way and provide safer roadsides. That translates into the laws related to trees within a road's right-of-way (which is typically wider than the actual paved or gravel travelway).

Who “owns” the trees in a right-of-way?
  • Determining ownership is the first step in the process when trees are in a public right of way.
  • The owner of a tree is the landowner on whose land the tree is rooted.
  • A very large percent of state-and town-maintained roads are not owned by the state or town (they are easements). Ownership belongs to the adjacent property.
  • Along those few “fee highways” in Maine, the state or town actually owns that land through an acquisition process and it includes the air above and the earth below.
  • If a trunk is split by a property boundary, the tree is owned by both parties. Decisions should be made by mutual consent of both parties.
  • Whoever OWNS the right-of-way, OWNS the trees.
Who is responsible for these trees?
  • Owners are responsible for preventing hazards that their trees may present, including to the travelling public. They may be held accountable if the tree causes property damage, bodily harm, or death.
  • MaineDOT and municipalities may remove hazardous trees that pose a serious threat to the travelling public without landowner permission.
  • The owner has “first right of refusal’ for the wood.
What should a municipality be concerned about?
  • A municipality’s obligation to keep town ways “safe and convenient” includes the duty to remove roadside brush, trees and grass that could pose a road safety problem. Uncontrolled brush can limit sight distances and in some cases may intrude onto the travel way itself.
  • The municipality may at its expense remove healthy or dead trees located within the right of way if they pose a safety hazard to the traveling public or impede the municipality’s ability to maintain the road.
  • On a local road, if a tree is located in the right-of-way but is not (in the determination of the municipal officers or road commissioner) a safety hazard, then the municipality is under no duty to remove it, even if the abutter requests removal.
  • If the reason for removing the tree is to protect an abutter’s house or property, rather than the traveling public, then the abutter should pay the costs of removal.
  • Trees located outside the road right of way should not be removed by the municipality without the landowner’s permission.
  • The municipality may cut any limbs in the air or roots on the ground that intrude into the right of way, even if the trunk of the tree is outside the right of way.
  • Consider appointing a tree warden, budgeting, and planning for removals. Write an action plan.
  • Always work with the landowner.
  • If in doubt on state roads, contact MaineDOT’s Bob Moosmann at 207-592-0774 or . He can assess hazards and assist in understanding how to proceed.
Trees and Maine law

Maine law governs trees in Title 30-A, Chapter 157, Subchapter 4. Some of the highlights are:

  • All trees within or upon the limits of any highway are public shade trees (Section 3281).
  • All public shade trees may be under the care and control of conservation commissioners in municipalities which appoint those commissioners under this subchapter. The conservation commissioners may have the powers and duties of tree wardens in regard to those trees (Section 3263).
  • The municipal officers of municipalities which have not appointed conservation commissioners under subchapter II may annually appoint one or more tree wardens who have the care and control of all public shade trees upon and along the highways and in the parks of the municipality and all streets within any village limits. They shall enforce all laws relating to the preservation of those trees (Section 3282).
  • Public shade trees may be trimmed, cut down or removed by the owner of the land only with the consent of a tree warden or the conservation commission. Public shade trees may be trimmed, cut down or removed by a tree warden or conservation commissioner only with the consent of the landowner (Section 3283). However, this section does not prevent the trimming, cutting or removal of trees when the trimming, cutting or removal is ordered by proper authority to:
    • Lay out, alter or widen the location of highways;
    • Lessen the danger of travel on highways; or
    • Suppress tree pests or insects.
Signs In The Right of Way

Campaign Signs Signs in the right-of-way of public roads are covered under state law found in Title 23, �1913-A.

See paragraph L for details about spacing and maximum time periods. Please note that the Legislature passed LD 209, as Public Law Chapter 321 on 2/18/2018 that will 1) change the 6 weeks to 12 weeks and, 2) creates a date the sign was erected. This becomes effective on August 1, 2018.

For specific details, contact MaineDOT"s Susan Merriman at or call her at 207/624-3332.

Design Standards for Local Roads

Any modern public road in Maine should be built to certain minimum standards that consider the traffic volume, type and size of vehicles, presence of pedestrians or bicycles, and overall safety to all road users.

  • For subdivisions roads:  
    The Southern Maine Regional Planning Commission (SMRPC) developed a set of “ Model Subdivision Regulations ” in the 90’s and they were updated in 2007.  They are primarily for subdivision design and review.
  • For low volume local roads:
    AASHTO has a manual entitled “Guidelines for Geometric Design of Low-Volume Roads (ADT less than 2000), 2nd edition, 2019.” This very handy manual references recommended ranges of values for dimensions such as road widths, horizontal and vertical alignments, sight distances, etc. The manual can be found here and costs $122 for a non-member PDF copy; however, the Center has a copy of the 1st Edition if you ever wanted to review it first or needed specific information.
  • The Center has also developed a road “cross section” that graphically shows the “desirable minimum dimensions” of a low volume local road: Desirable Minimum Dimensions  (PDF)
How a Pothole Forms

Potholes begin after moisture seeps into the native soil below the road surface and subbase gravel. This moisture comes in the form of rain, snow or water seeping into the road bed due to poor roadside drainage.

This is step one in the formation of a pothole

As the temperatures drop ice lenses of frozen water form,causing the ground to expand and push the pavement up as this is the direction of least resistance.

This is step two in the formation of a pothole

As the temperatures rise, the ground returns to normal level but the pavement often remains elevated above the once frozen area. This creates a cavity between the pavement and the material below it.

This is step three in the formation of a pothole

When motor vehicles travel over this cavity, the pressure exerted on the unsupported pavement surface cracks after numerous impacts of vehicles traveling over the cavity. Finally the pavement crumbles and falls into the cavity, leading to a pothole.

This is step four in the formation of a pothole

Dig Safe
  • Maine law regarding Dig Safe
  • Dig Safe website: This site has all the information you need to properly make “excavations” in Maine along with using 8-1-1 or their “quick ticket” system.
  • Grading gravel roads: a shoulder grading activity is now well defined and provides a method for this activity to occur without being in direct conflict with the law. Before this change, any grader blade which came closer than 18 inches in depth to the buried utility line was automatically in violation. Now, it is allowable ONLY IF the following occurs:
    • the excavator calls Dig Safe and all other nonmembers, as usual,
    • the excavator contacts each utility operator in the grading area and describes the proposed grading activity and includes the expected depth of grading,
    • within 3 days of this contact, the utility operator determines and notifies the excavator whether the faciltity is deep enough to avoid damage,
    • after this discussion, the excavator can grade the shoulders so as not to disturb the facility.
    • if the facility is not deep enough to allow the grading activity, the licensing authority (town or state, as applies), may require the utility operator to lower or otherwise move its facility in accordance with state law or its license, before the shoulder grading occurs.
  • Installing street name signposts
    • Street name signs and posts for E-911: Because the installation of sign posts is considered an "operation in which earth, rock, or other material BELOW the ground is moved or otherwise displaced," municipalities should call DIGSAFE before installing these posts. You can either call them with the locations (e.g., northwest corner of Elm and Maple Street) OR FAX the list to them at 781-721-0047. They will then assign authorization numbers to each site and FAX the list back to you. (Don't forget to premark the sites!)
    • Some people have questioned their liability if installing sign posts by hand or by power equipment. State law specifies that the use of power tools or equipment requires DIGSAFE notification. Digging, pounding, or trenching with hand tools is NOT considered excavation. However, what happens when road crew member Brutus drives a U-channel sign post with a sledgehammer right through a fiber-optic cable? Liable or not? State law says no, but this would probably create some interesting discussion between several attorneys. The bottom line is: make the free phone call, especially if you suspect any possibility of underground facilities.